Write An Article For Magazine Essay Example for Free

Write An Article For Magazine Essay I am reporting as both a child psychologist and a concerned parent, on the matter of the content of teenage magazines. My own daughter made me aware of this issue when I decided to look through one of her Bliss magazines; I discovered what kinds of stories were printed in them and others teenage magazines such as sugar. I was both shocked and concerned by the material printed in the teen mags and decided that I should write this article to inform other parents of the content of them. The magazines I researched were; Bliss which is aimed at 14-17 year olds and Sugar which is aimed at 13-19 year olds, considering the graphic and persuasive nature of the content of these magazines, this seems, to me, to be an inappropriate age range. Advertisement Archive The magazines are over-spilling with desirable products, which is yet another attraction for teenage girls. On average the magazines contain 17. 5% of advertisements of up-to-date fashion items such as clothes, shoes and fragrances. Some of the products are far too expensive for a teen budget; endless pages of shoes and make-up are sending the wrong signals to impressionable young girls. It tells them that expensive frocks and loads of make-up is what they should have to be in. How many of you have heard the line but mum I need it all my friends have got one. Why? Because like their friends they have been influenced by the media and manipulated into thinking they need named brands to look and feel good. Cheaper high street brands have been advertised more frequently on television, these magazines should adopt the same tactic. This would make teenagers feel more comfortable wearing high street brands and prevent parents from feeling inadequate for not being able to provide the latest Gucci handbag. Real Life Horrors I was kidnapped and sold to a brothel Bliss December 2006 My midnight escape from a sick cult Sugar December 2006; these are just some of the shocking headlines which featured in the magazines I looked at. Is this the kind of literature you thought your daughter was reading? These are not the kind of real issues I would have thought of as appropriate for the 13 year old readers of these magazines. Some of the stories I read, including the ones I have already mentioned, incorporated some vulgar and sometimes quite disturbing details such as as I came round, I vomited on the floor. My head hurt and I was bleeding between my legs the story continued along the same lines in a very descriptive manner. Stories such as these rarely occur in real life and are scare mongering, and can be very disturbing for young readers. These articles do often include help lines enabling teenagers to contact an adult, however I think it highly unlikely that these articles would relate to an average British teenage girl. Though these stories are not stories that teenage girls relate to, they seem very interested in them. This makes me very uncomfortable as a parent and as a child psychologist as I find it difficult to associate the interest in such horrendous articles, to the other interests of the average teenager. I think that stories that relate to the more common occurrences in a teenagers lifes, such as sporting achievements and charities, which they could get involved in would be more appropriate. Picture Perfect All the magazines feature flawless models, dressed to impress on the front covers, with headlines such as 184 a-list model looks and sexiest party fashion. To my 14-year-old daughter and young girls like her, these images are ones that they aspire to. With pictures coupled with the headlines, the covers entice them into the materialistic fashion obsessed world of the a-list celeb. The immaculate appearance of the models is simply not a realistic view of an average teenager, theyre even often air-brushed; the images portrayed could make young girls feel inadequate purely because of natural teenage blemishes. Maybe images of everyday teens would provide a more pragmatic outlook to ordinary girls. The covers are plastered in bright coloured text in varying fonts and offer various stereotypical girly gifts such as pink lip-glosses for that perfect pout. These eye-catching fonts and free gift offers draw the young reader in, encouraging them to buy the over-priced magazines. The magazines are about i 2. 50 each which I would consider to be fairly expensive for a teenager as they usually buy several of these magazines with their pocket money, which is typically in the region i 5 to i 10. To me, as a parent, such magazines would be more acceptable if they were at a more reasonable price and featured fewer stories about celebrities shocking secrets, and more about achievements and real issues.

Visual Information Encryption by D-H Key Agreement

Visual Information Encryption by D-H Key Agreement Visual Information Encryption by D-H Key Agreement and Visual Cryptography Abstract Visual cryptography provides secured digital transmission which is used only for one time. In order to make visual cryptography reusable Diffie and Hellman (D-H) key is used. The original images can be reuse by using this scheme. It is effortless and uncomplicated technique to execute the secret image for shadow images. The shadow images are the shrunken version of the original image, in which the secret image share is embedded. These are used to guard the data and secret images in the internet so that it is not accessed by any unauthorized persons. Visual cryptography divides the image into secret shadow images. After this these shadow images are distributed in the original image. Recovering of secret image is done by human visual system by piling all the shadow images. As this Visual cryptography is used only once D-H key agreement was used to make it reusable by using D-H key scheme in it. Objectives: Provision of security for hidden images Reusing of the original image is possible by this technology Images should be visible only to human visual system Literature Review In this project a visual cryptography scheme is used for encrypting the information. Visual cryptography is an encryption method which is used to hide the information in an image, decrypted can be done by human visual system. By using only this scheme the reusing is not possible. The image which is recovered after decryption will not be same as original image so it cannot be reused. For the reuse of the visual cryptography Diffie and Hellman (D-H) key agreement method and Toral Automorphism (TA) can be used. In this both secret and symmetry-key representation can be used (Chao-Wen Chan and Yi-Da Wu, 2008). Visual cryptography is the scheme which facilities the secret sharing of the pictures or data. The pixels of the pictures or data that need to be transmitted secretly will be treated as an individual secret which can be shared using a secret sharing scheme. The picture is first split into two or more shared images the secret data are embedded. At the decryption side images are join ed on the transparent paper to get the secret picture or data. This is the way in which the first visual cryptography was started (Borivoje Furht, Edin Muharemagic and Daniel Socek, 2005). Using current methods the Visual cryptography scheme will allow the encoding of the secret image into shares; this is done in the form of transparencies. These shares are distributed to the participants, such that only the qualified subsets of participants can recover the secret image visually. This is done by superimposing the share images one over the other which are obtained from the original image (Carlo Blundo and Stelvio Cimato, 2005). In this scheme the devices are used for encoding of secret information and the decoding is done with human vision directly. For encoding, the visual cryptography will cryptographically encode the binary secret data into shares of the pattern which will be random. Then the shares are copied on to the transparencies with the same number of transparencies as shar es. The transparencies are distributed among the participants, one for each participant. The decoding of the data or picture is done only when all of the participants superimpose their transparencies (Alan Conrad Bovik, 2005). The importance of this scheme is that there is no need for data expansion. The resolution of the data will not be lost by using this scheme. By using this scheme the image will be secure against the most important cryptanalytic attacks. The computation complexity will be less since it involves only XOR operations. By using XOR operations the share images are combined to form the encrypted images. The authentication of the image will be based on the global visual effect, so local defects due to noise will not affect the final result. The most important aspect of this scheme is that the decoding of the secret data or image can be done with human vision without any decoding equipment (Kiyoharu Aizawa, Yuichi Nakamura and Shinichi Satoh, 2004). The previous techno logies that came into existing before visual cryptography are two-out-of two visual threshold schemes, two-out-of-n visual-threshold scheme. In a two-out-of two visual threshold scheme the secret can be any type of data (Abhishek Parakh and Subhash Kak, 2006, p.1). For an image comprising of white and black pixels, this image can be encoded as a binary string. In this scheme the 0 will represent a white pixel and 1 represents a black pixel and the result will be sent in two shares. The security problem by this is having only 50 percent of resolution will be obtained because the image is divided into only two shares and if the new shares of data are found the image can be decrypted very easily. A two-out-of-n visual-threshold scheme is more secure when compared with the first. In this scheme also the pixels are divided into two, but the shares will be n. By this the security will increase. When compared with the D-H key agreement the resolution of these schemes will be less and secur ity will also be less (Doug Stinson, 1999). The D-H key agreement is used to make possible the reuse of visual cryptography. The Diffie-Hellman key agreement used an interface known as D-H key interface. This interface is used for password based Encryption. These interfaces typically can be used by the programmer who is implementing a Cryptographic provider or who wants to implement a cryptography algorithm (David Flanagan, 2005). Diffie- Hellman Key agreement is also known as exponential key exchange. This key provides the solution to the key distribution problems, allowing two parties, never having met in advance to share key material for establishing a shared secret by exchanging messages over an open channel. This is a fundamental technique providing unauthenticated key agreement. The main goal of an authenticated Key establishment protocol is to distribute key of data. The established key should have precisely the same attributes as a key established face to face, it should be distributed uniformly at random from the key space, and an unauthorized entity will not be able to learn anything about the key (Alfred J.Menezes, Paul C. Van Oorschot, and Scott A. Vanstone, 1997). D-H key agreement protocols involve the derivation of the shared secret information based on compatible D-H keys between the sender and recipient. The information is then converted into the cryptographic keying material for other algorithms. A variation of the Diffie-Hellman is used for converting the shared secret data into an arbitrary amount of keying materials (Manuel Mogollon, 2008). According to Michael Baake and John A G Roberts (2001, p.1) Toral Automorphisms will be represented by the uni-modular integer matrices, are investigated with the help of symmetries and also reversing symmetries group of matrices with a simple spectrum through their connection with unit groups in orders of algebraic number fields. The reversibility will derive the necessary conditions in terms of the distinctive polynomial and the polynomial invar iants. This shows that the Voiculescu- Brown entropy of the non-commutative toral automorphism arising from a matrix S in is at least half the value of the topological entropy of the corresponding classical toral automorphism. This is a new method used to prove the position limit laws in the theory of dynamical systems, which is based on the Chen-Stein method combined with the analysis of the homo clinic Laplace operator and some other homo clinic considerations (Massimo Franceschetti and Ronald Meester, 2002, p.2). The main use of this is to generate a disorder in the arrangement of digital images. The equation (1) define the two dimensional matrix. The new technology that can be used for the visual cryptography is adaptive order dithering technique. By using this technique the decrypted image size can be reduced and also the quality of decryption image can be improved. In this technique the technique will get adaptive to the data that is used (Nagaraj V. Dharwadkar, B.B. Amberker and Sushil Raj Joshi, 2009). From the above context it can be understood that visual cryptography is a scheme in which the secret data can be transmitted without getting decoded by others. Chapter 1: Introduction 1.1. Overview Visual Information system significantly enlarges the applications scope of information systems and typically deals with the general purpose multimedia operating system that is supported by multimedia hardware and high bandwidth network. Visual information system involves variety of facilities for efficient visual information presentation and visualization. This system actually provides inter related visual and multimedia information to support the operations, management and decision making functions in an organization. These are text oriented which provides reports, decision-making information and documents for all levels of hierarchy in the organization. With the increase in multimedia platforms, visual information has become more available (Clement H. C. Leung, 1997). In recent years, there has been a rapid growth of information technology for human to communication on the Internet. Since Internet is public, with the advancement of information technology, communication through inte rnet has increased rapidly. As internet can be accessed by everyone and anyone can easily access the information and transmit it without any protection there is possibility of grabbing the information as it became secondary data. So in order to avoid hacking of sensitive information, it should be encrypted before transmission. In order to protect the information Diffie and Helman (D-H) proposed a key agreement scheme that is implemented when two parties agree on a common session key. This key agreement also helps in improving the reusable process. This method is used to compute a common image for encryption and decryption with two parties (Chao-Wen Chan and Yi-Da Wu, 2008). The D-H algorithm does not encrypt data or make a digital signature. This is exclusively used for the generation of shred secrets. The DH key agreement can be split into three parts; they are parameter generation that generates non secret public value and is expensive process, next is phase1generatres two key exc hange values for the parties and phase2 is the originator and recipient that computes the functions in the given image (Blake Dournaee, 2002). DH key agreement has a nice property that it is not sensitive to off-line attacks but it is sensitive to man-in-the-middle attacks (Christian Gehmann, Joakim Persson and Ben Smeets, 2004). In Diffie and Hellman (D-H) key agreement method both the secret and symmetry key are represented in binary image. It is simple and easy to be implemented especially for shadow images. Thus, it can be applied in many electronic business applications. There after Naor and Shamir proposed a methodology named visual secret sharing that provides secrecy to the information and avoids illegal activities; this process is called as Visual Cryptography. This process provides secrecy by partitioning the secret digital image into several shadow images that are recovered by the human visual system by piling all those images together (Jeng-Shyang Pan, Hsiang-Cheh Huang and L. C. Jain, 2004). Hence it can be stated that in order to safeguard the images visual cryptography and DH key agreement are used where the images are split into shadow images and sent which then will be combines and viewed by the human visual system. It is secured by encryption and decryption of images with a key to be presented. Visual cryptography is seen as a one time pad system that cannot be reused, in further sections of the study the implementation of Diffie and Hellman (D-H) key agreement method is researched in detail so that visual cryptography can be reused. 1.2. Aims and Objectives Aim: To research on visual information encryption by D-H Key agreement and visual Cryptography Objectives: Provision of security for hidden images Reusing of the technology again and again Images should be visible only to human visual system 1.3. Purpose of Study The main purpose of studying the Visual Encryption is to provide a unified overview of techniques for the encryption of the image and video data, ranging from commercial applications like DVD or DVB to more research oriented topic and recently published material. To serve this purpose of Visual Encryption has the different techniques of a unified viewpoint, it provide an extensive use of Visual Encryption. Digital visual data is usually organized in a rectangular arrays denoted as frames, the elements of these array are denoted as pixels. Each pixel is a numerical value specifies the intensity of the pixels (Andreas Uhl and Andreas Pommer, 2005). In the latest year, there has been a rapid growth of the information technology for the human to communication on the Internet. As Internet has become the open public, anyone can easily read information and perform the successful transmission of the information without protection. In order to provide the proper security to the information, V isual Information Encryption by D-H Key study is necessary (chao-Wen and Yi-Da Wu, 2008). Visual Information Encryption provides the secure connection and protects data from unexpected modification by hackers or other outsiders. In D-H key encryption a common password is required for all the attendees to participate in the same conference, which gives more security to the information (Encryption, 2008). Visual information Encryption provides the Encryption formats as a standard function. Thus, the main purpose of the study is to implement a visual secret sharing scheme through visual cryptography in order to avoid sensitive information being illegally read or modified because the observations made from the recent electronic business applications on the Internet reveal that the amount of data exchanged is small and the exchanged data requires secrecy. 1.4. Research Context With the rapid increase in visual information, the digital and video encryption approaches are widely studied upon various resources like visual net meetings. This application mostly requires ultra high security to keep the images and video dat confidential among users; nobody can retrieve the content without a key for decryption. Thus, from this point of view image encryption is considered as a basis for visual encryption. Visual Cryptography is a topic that finds its way into every nook and cranny of the networking world. Everyone has their own ideas of how it should work and their own understanding of how it does work. The problem with the encryption is that there are several different types, and these type works in several different ways. And most companies want encryption, they dont necessarily know what type of encryption they want, and what the difference are between the types. Here this is designed to give a good overview of the current encryption technology (Eric Quinn, 2009 ). The visual cryptography is mainly used in maintaining images secretly for not to be accessed by the unauthorized persons. By using this technology the images can be visual by the user but it cannot be accessed by unauthorized persons. As there is increasing growth in the computer networks and in distributed a computing application visual cryptography plays an important role in providing security (visual cryptography, 2009). In binary images scheme the visual cryptography helps in maintaining the secrecy for not providing authorization to intruders. The visual cryptography provides an infinite computation power that messages cannot be identified. This visual cryptography is in identification of bank customers, verification of electronic voting and anti spam bot measures for maintaining the secrecy to avoid intruders Visual cryptography provides a way for secretly maintaining the information and data. Visual cryptography is used in many applications for maintaining data secretly fo r not be authorized by the intruders (Nagaraj V. Dharwadhakar, Amberker and susil Raj Joshi, 2009). This system actually supplies inter related visual and multimedia information to support the operations, management and decision making functions in an organization. This process provides confidentiality by dividing the secret digital image into several images that are healthier by the human visual system by those images together. Visual cryptography strategy is suggested to combine the key agreement scheme with a shadow image without building a secure connection. Thus, visual cryptology uses public key algorithm for having maintain secretly (Kiyoharu Aizawa, Yuichi nakamura and shinichi satoh, 2004). Many organizations are using this methodology for not having interruptions in data. Visual cryptography uses different encryption and decryption techniques and many authentications for not be accessed by unauthorized persons and maintains secrecy. In this research D-H key algorithm is us ed for having secrecy and privacy can be maintained. By implementation of new encryption schemes provides secrecy in an effective manner. 1.5. Research Method Qualitative approach is appropriate for this research method. Qualitative Research Practice starts with the premise that one can improve their research skills by seeing what researchers actually do in particular projects and by adding their actions and plans into their own research practice. It actually demonstrates the benefits of using practical methods from real-life knowledge and will be necessary reading for anyone interested in the process of doing social research (Clive Seale, 2004). It is a field of inquiry that explains discipline and subject matters. It is called as ethnographic research. It involves collection of narrative data in a natural setting in order to gain insights into phenomenon of interest. This research studies many variables over an extensive period of time to find out the way things are, how and why they came to be that way and what it all means. Qualitative researchers do not want to interfere or control anything. The most common method of data collection i nvolves participant observation (Michael Huberman Matthew and Miles, 2002). Qualitative analysis offers a cluster of very useful procedures like guidelines, techniques etc. It actually refers to the educational issues and the understanding of learning and cognition (Pamela S. Maykut and Richard Morehouse, 1994). Hence, it can be said that the secondary data is preferred for this research while searching the related information to it as the other approaches cannot provide a better data to the research. Chapter 2: Literature Review 2.1. Overview Visual Cryptography is a particular encryption method used to hide information in images in such a way that it can be decrypted by the human visual system if the correct key image is applied. This method was suggested by Naor and Shamir in 1994. Visual Cryptography applies two transparent images. One image consist random pixels and the other image consist of the secret information. In visual cryptography it is not possible to recollect the secret information from one of the images. Both transparent images and layers are involved to reveal the information (Kiyoharu Aizawa, yuichi Nakamura and shichi satoh, 2004). The simplest method to implement Visual Cryptography is to bring out the two layers against a transparent sheet. When the random image contains genuinely random pixels then it can be seen as a onetime pad system and will offer infrangibly encryption. In visual cryptography pixel is divided into white and black blocks. In this chapter, importance of visual cryptography is disc ussed and a New Visual information Encryption Scheme is proposed followed by the explanation of Security analysis on images with the previous technologies. 2.2. Visual Cryptography Visual Cryptography refers to a secret sharing method that will encrypt the secret message into a number of shares and does not require any computer or calculations for decrypting the secret image rather the secret message will be reconstructed visually by overlaying the encrypted shares the secret image will become clearly visible. Visual cryptography scheme on a set P of n participants can be defined as a method of encoding the secret image into n shares so that the original image will be obtained by stacking specific combination of shares onto each other. Visual cryptography technique was initiated by the Naor and Shamiri at Eurocrypt 94. It is a process used for separating one image into various shares. Visual cryptography solutions functions on binary inputs. Visual cryptography is a special technique used to hide information in images in such a way that it can be decrypted by the human vision when the correct image is used. It uses two images one image contains secret informati on, in visual cryptography it is not possible to retrieve the secret information from one of the images, both transparent images are required to reveal the information. To print two layers into the transparent sheet is the simplest way to implement Visual cryptography (jeng shying pan, Hsiang cheh Huang and L. C. Jain, 2004). If the random image contains random pixel then it can be seen as a onetime pad system and will offer unbreakable encryption. These two layers slide over each other until they are correctly aligned where the hidden information appears. This type of visual cryptography which restores the image by stacking some significant images together is known as extended visual cryptography. Generally, visual cryptography suffers from the deterioration of image quality. The basic two cryptography models consists of a secret message encoded into two transparencies, one transparency representing the cipher text and the other acting as a secret key. Both transparencies appear to random dots when inspected individually and does not provide any information about the original clear text. By carefully aligning the transparencies the original message is reproduced (Borivoje Furht, Edin Muharemagic and Daniel socek, 2005). The original decoding is accomplished by the human visual system. Visual cryptography scheme is a visual secret sharing problem in which the secret message is viewed only in black and white pixels. Each pixel in the original image is represented by at least one sub pixel in each of the n transparencies or shares generated. Each share is comprised of collection of m black and white sub pixels where each collection represents a particular original pixel. The contrast of Visual Cryptography Scheme is the difference between the minimum number of black sub pixels in a reconstructed (secret) black pixel and the maximum number of black sub pixels in a reconstructed (secret) white pixel (Kiyoharu Aizawa, Yuchi Nakamura and Shinichi Satoh, 2004). The m ain instantiation of visual cryptographic realizes a cryptographic protocol called secret sharing. The important thing in secret sharing is it relies on a human visual system to perform the decryption. In a conventional secret sharing a secret shared among n participants can pull their shares and recover the secret but the subsets of the forbidden can obtain no information about that. Visual secret sharing schemes inherits all applications of conventional secret sharing schemes most notably access control. An example of the encoding of white and black pixels in a 2 out of 2 scheme can be seen in Figure 1. Here two shares out of the two generated would be needed to recover the original image. Since only two shares are generated, n = 2. White box represents a single white or black pixel in the original image. Sub pixel assignments that would be given to shares #1 and #2 respectively. The number of sub pixels per share used to represent the original pixel is four Finally, the overall visual effect when shares #1 and #2 are correctly aligned on top of one another. Notice that when the shares in this example are combined the original black pixel is viewed as black; however, the original white pixel takes on a grey scale. The structure obtained from either white or black pixel representation can be described by an n. Similar to the area of the secret sharing, more generally structures have been studied in the visual cryptography. The basic model of the visual cryptography consists of a sever al umber of transparency sheets. On each transparency a cipher text is printed which is identical from random noise. The hidden message is reconstructed by stacking a certain number of the transparencies and viewing them. The system can be used by anyone without any knowledge of cryptography and without performing any cryptographic computations. Naor and Shamir have developed the Visual Secret Sharing Scheme (VSSS) to implement this model [Naor95] (Mizuho Nakajima and Yasushi Yamaguchi, 2002). Thus, from the above discursion it can be stated that Visual cryptography is a special technique used to hide information in images in such a way that it can be decrypted by the human vision when the correct image is used. It is a simple and clear scheme that can partition the secret image into a number of shadow images and the dealers can distribute these shadow images to participants. The Visual cryptography scheme makes use of human visual system for recovering secret images by staking vari ous shadow images. 2.3. Importance of Visual Cryptography Visual Information system importantly elaborates the diligences scope of information systems and deals with the multimedia operating system which is supported by multimedia hardware and high bandwidth network. These are text oriented which provides reports, decision-making information and documents for all levels of hierarchy in the organization (Carlo Blundo and Stelvio, 2005). With the increase in multimedia platforms, visual information has become more available with the advancement of information technology; contact through internet has increased rapidly. Visual information system requires many kinds of facilities for effective visual information presentation and visualization. This system actually supplies inter related visual and multimedia information to support the operations, management and decision making functions in an organization. As internet can be accessed by everyone and anyone can easily access the information and transmit it without any protection there is possibil ity of grabbing the information as it became secondary data. So in order to avoid hacking of sensitive information, it should be encrypted before transmission (Yongfei Han, 1997). In order to protect the information Diffie and Helman (D-H) proposed a key agreement scheme that is implemented when two parties agree on a common session key. This key agreement also helps in improving the reusable process. This technique is utilized to calculate a common image for encryption and decryption with two parties. The D-H algorithm does not encrypt data or make a digital signature. This is exclusively used for the generation of shred secrets. The DH key agreement can be split into three parts; they are parameter generation that generates non secret public value and is expensive process, next is phase1generatres two key exchange values for the parties and phase2 is the originator and recipient that computes the functions in the given image. DH key agreement has a nice property that it is not sen sitive to off-line attacks but it is sensitive to man-in-the-middle attacks. There after Naor and Shamir proposed a methodology named visual secret sharing that provides secrecy to the information and avoids illegal activities (Jeng-Shyang Pan, Hsiang-Cheh Huang and L. C. Jain, 2004). This process is called as Visual Cryptography. This process provides secrecy by partitioning the secret digital image into several shadow images that are recovered by the human visual system by piling all those images together. It is secured technique where the data cannot be traced by others. In classic secret sharing, algorithms for splitting and sharing secret information are a stem of cryptography. In the most general case, their objective is to generate such parts for the data and that could be shared by multiple authorized persons. This problem of splitting information in a manner allowing its reconstruction by a certain n-person group interested in the reconstruction of the split information. Al gorithm solutions developed to achieve this objective and at the same time none of the groups of participants in such a protocol, whose number is lesser than the required m persons. It leads to opposing to read the split message. The algorithms for dividing information make it possible to split it into chunks known as shadows that are later distributed among the participants of the protocol. So that the shares of certain subsets of users collective together and these are capable of reconstructing the original information. There are two groups of algorithms for dividing information, namely, secret splitting and secret sharing. In the first technique, information is distributed among the participants of the protocol, and all the participants are required to put together their parts to have it reconstructed. A more universal method of splitting information is the latter method, i.e. secret sharing (Marek R. Ogiela and Urszula Ogiela, 2009). Thus, from the above discursion it can be sta ted that visual cryptography plays a vital role in securing the data and also in sharing the secret message as the data transferred through internet has been increased. rapidly. Advantages of visual cryptography Visual cryptography is simple to be implemented. Encryption incase of visual cryptography does not require any hard problem dependency. Specifically decryption algorithms are not required because a person aware of cryptography can easily decrypt the message. Cipher text can be Fax or e-mail in case of visual cryptography 2.4. Security analysis on images with the previous technologies The security analysis is the major aspect of the encryption. Analysis to the field of security will encounter the serious obstacle that deal is by nature not an exact science. The previous technologies which where there before the D-H key agreement encryption are manual encryption, transparent encryption, symmetric encryption and asymmetric encryption (Fedora Documentation Project, 2009). Visual cryptography can be seen as a one-time pad system. Then, it cannot be reused. Diffie and Hellman (D-H) key agreement method and Toral Automorphism (TA) such that visual cryptography can be reused. Both secret and symmetry-key are represented in binary image. The proposed scheme is simple and easy to be implemented for shadow images. Therefore, it can be used in many electronic business applications (Chao-Wen Chan and Yi-Da Wu, 2008). The Manual Encryption is a technique that will involve the use of encryption software. In this computer programs are used for encrypt various bits of information digitally. In this technique the encryption key is provided later in the process. The main security issues are the potential leakage through security insensible program and also the bad implementation may lead to re-encrypt with same key for same password (Bruice Schneier, 2007). Transparent Encryption is another type of computer software encryption. In this technique the data can be downloaded onto a computer to encrypt automatically. Every executable application and file created in the computer has an encrypted copy that can withstand power surges and protects information in case a computer is stolen. The security issues is the data which is automatically encrypted can be taken if the key provided is known (Cetin K. Koc, David Naccache and Christof Paar, 2001). The Symmetric Encryption is in which a letter or number coincides with another letter or number in the encryption code. This technique is commonly referred to as secret-key encryption. In this only single key is used for e ncrypting an Visual Information Encryption by D-H Key Agreement Visual Information Encryption by D-H Key Agreement Visual Information Encryption by D-H Key Agreement and Visual Cryptography Abstract Visual cryptography provides secured digital transmission which is used only for one time. In order to make visual cryptography reusable Diffie and Hellman (D-H) key is used. The original images can be reuse by using this scheme. It is effortless and uncomplicated technique to execute the secret image for shadow images. The shadow images are the shrunken version of the original image, in which the secret image share is embedded. These are used to guard the data and secret images in the internet so that it is not accessed by any unauthorized persons. Visual cryptography divides the image into secret shadow images. After this these shadow images are distributed in the original image. Recovering of secret image is done by human visual system by piling all the shadow images. As this Visual cryptography is used only once D-H key agreement was used to make it reusable by using D-H key scheme in it. Objectives: Provision of security for hidden images Reusing of the original image is possible by this technology Images should be visible only to human visual system Literature Review In this project a visual cryptography scheme is used for encrypting the information. Visual cryptography is an encryption method which is used to hide the information in an image, decrypted can be done by human visual system. By using only this scheme the reusing is not possible. The image which is recovered after decryption will not be same as original image so it cannot be reused. For the reuse of the visual cryptography Diffie and Hellman (D-H) key agreement method and Toral Automorphism (TA) can be used. In this both secret and symmetry-key representation can be used (Chao-Wen Chan and Yi-Da Wu, 2008). Visual cryptography is the scheme which facilities the secret sharing of the pictures or data. The pixels of the pictures or data that need to be transmitted secretly will be treated as an individual secret which can be shared using a secret sharing scheme. The picture is first split into two or more shared images the secret data are embedded. At the decryption side images are join ed on the transparent paper to get the secret picture or data. This is the way in which the first visual cryptography was started (Borivoje Furht, Edin Muharemagic and Daniel Socek, 2005). Using current methods the Visual cryptography scheme will allow the encoding of the secret image into shares; this is done in the form of transparencies. These shares are distributed to the participants, such that only the qualified subsets of participants can recover the secret image visually. This is done by superimposing the share images one over the other which are obtained from the original image (Carlo Blundo and Stelvio Cimato, 2005). In this scheme the devices are used for encoding of secret information and the decoding is done with human vision directly. For encoding, the visual cryptography will cryptographically encode the binary secret data into shares of the pattern which will be random. Then the shares are copied on to the transparencies with the same number of transparencies as shar es. The transparencies are distributed among the participants, one for each participant. The decoding of the data or picture is done only when all of the participants superimpose their transparencies (Alan Conrad Bovik, 2005). The importance of this scheme is that there is no need for data expansion. The resolution of the data will not be lost by using this scheme. By using this scheme the image will be secure against the most important cryptanalytic attacks. The computation complexity will be less since it involves only XOR operations. By using XOR operations the share images are combined to form the encrypted images. The authentication of the image will be based on the global visual effect, so local defects due to noise will not affect the final result. The most important aspect of this scheme is that the decoding of the secret data or image can be done with human vision without any decoding equipment (Kiyoharu Aizawa, Yuichi Nakamura and Shinichi Satoh, 2004). The previous techno logies that came into existing before visual cryptography are two-out-of two visual threshold schemes, two-out-of-n visual-threshold scheme. In a two-out-of two visual threshold scheme the secret can be any type of data (Abhishek Parakh and Subhash Kak, 2006, p.1). For an image comprising of white and black pixels, this image can be encoded as a binary string. In this scheme the 0 will represent a white pixel and 1 represents a black pixel and the result will be sent in two shares. The security problem by this is having only 50 percent of resolution will be obtained because the image is divided into only two shares and if the new shares of data are found the image can be decrypted very easily. A two-out-of-n visual-threshold scheme is more secure when compared with the first. In this scheme also the pixels are divided into two, but the shares will be n. By this the security will increase. When compared with the D-H key agreement the resolution of these schemes will be less and secur ity will also be less (Doug Stinson, 1999). The D-H key agreement is used to make possible the reuse of visual cryptography. The Diffie-Hellman key agreement used an interface known as D-H key interface. This interface is used for password based Encryption. These interfaces typically can be used by the programmer who is implementing a Cryptographic provider or who wants to implement a cryptography algorithm (David Flanagan, 2005). Diffie- Hellman Key agreement is also known as exponential key exchange. This key provides the solution to the key distribution problems, allowing two parties, never having met in advance to share key material for establishing a shared secret by exchanging messages over an open channel. This is a fundamental technique providing unauthenticated key agreement. The main goal of an authenticated Key establishment protocol is to distribute key of data. The established key should have precisely the same attributes as a key established face to face, it should be distributed uniformly at random from the key space, and an unauthorized entity will not be able to learn anything about the key (Alfred J.Menezes, Paul C. Van Oorschot, and Scott A. Vanstone, 1997). D-H key agreement protocols involve the derivation of the shared secret information based on compatible D-H keys between the sender and recipient. The information is then converted into the cryptographic keying material for other algorithms. A variation of the Diffie-Hellman is used for converting the shared secret data into an arbitrary amount of keying materials (Manuel Mogollon, 2008). According to Michael Baake and John A G Roberts (2001, p.1) Toral Automorphisms will be represented by the uni-modular integer matrices, are investigated with the help of symmetries and also reversing symmetries group of matrices with a simple spectrum through their connection with unit groups in orders of algebraic number fields. The reversibility will derive the necessary conditions in terms of the distinctive polynomial and the polynomial invar iants. This shows that the Voiculescu- Brown entropy of the non-commutative toral automorphism arising from a matrix S in is at least half the value of the topological entropy of the corresponding classical toral automorphism. This is a new method used to prove the position limit laws in the theory of dynamical systems, which is based on the Chen-Stein method combined with the analysis of the homo clinic Laplace operator and some other homo clinic considerations (Massimo Franceschetti and Ronald Meester, 2002, p.2). The main use of this is to generate a disorder in the arrangement of digital images. The equation (1) define the two dimensional matrix. The new technology that can be used for the visual cryptography is adaptive order dithering technique. By using this technique the decrypted image size can be reduced and also the quality of decryption image can be improved. In this technique the technique will get adaptive to the data that is used (Nagaraj V. Dharwadkar, B.B. Amberker and Sushil Raj Joshi, 2009). From the above context it can be understood that visual cryptography is a scheme in which the secret data can be transmitted without getting decoded by others. Chapter 1: Introduction 1.1. Overview Visual Information system significantly enlarges the applications scope of information systems and typically deals with the general purpose multimedia operating system that is supported by multimedia hardware and high bandwidth network. Visual information system involves variety of facilities for efficient visual information presentation and visualization. This system actually provides inter related visual and multimedia information to support the operations, management and decision making functions in an organization. These are text oriented which provides reports, decision-making information and documents for all levels of hierarchy in the organization. With the increase in multimedia platforms, visual information has become more available (Clement H. C. Leung, 1997). In recent years, there has been a rapid growth of information technology for human to communication on the Internet. Since Internet is public, with the advancement of information technology, communication through inte rnet has increased rapidly. As internet can be accessed by everyone and anyone can easily access the information and transmit it without any protection there is possibility of grabbing the information as it became secondary data. So in order to avoid hacking of sensitive information, it should be encrypted before transmission. In order to protect the information Diffie and Helman (D-H) proposed a key agreement scheme that is implemented when two parties agree on a common session key. This key agreement also helps in improving the reusable process. This method is used to compute a common image for encryption and decryption with two parties (Chao-Wen Chan and Yi-Da Wu, 2008). The D-H algorithm does not encrypt data or make a digital signature. This is exclusively used for the generation of shred secrets. The DH key agreement can be split into three parts; they are parameter generation that generates non secret public value and is expensive process, next is phase1generatres two key exc hange values for the parties and phase2 is the originator and recipient that computes the functions in the given image (Blake Dournaee, 2002). DH key agreement has a nice property that it is not sensitive to off-line attacks but it is sensitive to man-in-the-middle attacks (Christian Gehmann, Joakim Persson and Ben Smeets, 2004). In Diffie and Hellman (D-H) key agreement method both the secret and symmetry key are represented in binary image. It is simple and easy to be implemented especially for shadow images. Thus, it can be applied in many electronic business applications. There after Naor and Shamir proposed a methodology named visual secret sharing that provides secrecy to the information and avoids illegal activities; this process is called as Visual Cryptography. This process provides secrecy by partitioning the secret digital image into several shadow images that are recovered by the human visual system by piling all those images together (Jeng-Shyang Pan, Hsiang-Cheh Huang and L. C. Jain, 2004). Hence it can be stated that in order to safeguard the images visual cryptography and DH key agreement are used where the images are split into shadow images and sent which then will be combines and viewed by the human visual system. It is secured by encryption and decryption of images with a key to be presented. Visual cryptography is seen as a one time pad system that cannot be reused, in further sections of the study the implementation of Diffie and Hellman (D-H) key agreement method is researched in detail so that visual cryptography can be reused. 1.2. Aims and Objectives Aim: To research on visual information encryption by D-H Key agreement and visual Cryptography Objectives: Provision of security for hidden images Reusing of the technology again and again Images should be visible only to human visual system 1.3. Purpose of Study The main purpose of studying the Visual Encryption is to provide a unified overview of techniques for the encryption of the image and video data, ranging from commercial applications like DVD or DVB to more research oriented topic and recently published material. To serve this purpose of Visual Encryption has the different techniques of a unified viewpoint, it provide an extensive use of Visual Encryption. Digital visual data is usually organized in a rectangular arrays denoted as frames, the elements of these array are denoted as pixels. Each pixel is a numerical value specifies the intensity of the pixels (Andreas Uhl and Andreas Pommer, 2005). In the latest year, there has been a rapid growth of the information technology for the human to communication on the Internet. As Internet has become the open public, anyone can easily read information and perform the successful transmission of the information without protection. In order to provide the proper security to the information, V isual Information Encryption by D-H Key study is necessary (chao-Wen and Yi-Da Wu, 2008). Visual Information Encryption provides the secure connection and protects data from unexpected modification by hackers or other outsiders. In D-H key encryption a common password is required for all the attendees to participate in the same conference, which gives more security to the information (Encryption, 2008). Visual information Encryption provides the Encryption formats as a standard function. Thus, the main purpose of the study is to implement a visual secret sharing scheme through visual cryptography in order to avoid sensitive information being illegally read or modified because the observations made from the recent electronic business applications on the Internet reveal that the amount of data exchanged is small and the exchanged data requires secrecy. 1.4. Research Context With the rapid increase in visual information, the digital and video encryption approaches are widely studied upon various resources like visual net meetings. This application mostly requires ultra high security to keep the images and video dat confidential among users; nobody can retrieve the content without a key for decryption. Thus, from this point of view image encryption is considered as a basis for visual encryption. Visual Cryptography is a topic that finds its way into every nook and cranny of the networking world. Everyone has their own ideas of how it should work and their own understanding of how it does work. The problem with the encryption is that there are several different types, and these type works in several different ways. And most companies want encryption, they dont necessarily know what type of encryption they want, and what the difference are between the types. Here this is designed to give a good overview of the current encryption technology (Eric Quinn, 2009 ). The visual cryptography is mainly used in maintaining images secretly for not to be accessed by the unauthorized persons. By using this technology the images can be visual by the user but it cannot be accessed by unauthorized persons. As there is increasing growth in the computer networks and in distributed a computing application visual cryptography plays an important role in providing security (visual cryptography, 2009). In binary images scheme the visual cryptography helps in maintaining the secrecy for not providing authorization to intruders. The visual cryptography provides an infinite computation power that messages cannot be identified. This visual cryptography is in identification of bank customers, verification of electronic voting and anti spam bot measures for maintaining the secrecy to avoid intruders Visual cryptography provides a way for secretly maintaining the information and data. Visual cryptography is used in many applications for maintaining data secretly fo r not be authorized by the intruders (Nagaraj V. Dharwadhakar, Amberker and susil Raj Joshi, 2009). This system actually supplies inter related visual and multimedia information to support the operations, management and decision making functions in an organization. This process provides confidentiality by dividing the secret digital image into several images that are healthier by the human visual system by those images together. Visual cryptography strategy is suggested to combine the key agreement scheme with a shadow image without building a secure connection. Thus, visual cryptology uses public key algorithm for having maintain secretly (Kiyoharu Aizawa, Yuichi nakamura and shinichi satoh, 2004). Many organizations are using this methodology for not having interruptions in data. Visual cryptography uses different encryption and decryption techniques and many authentications for not be accessed by unauthorized persons and maintains secrecy. In this research D-H key algorithm is us ed for having secrecy and privacy can be maintained. By implementation of new encryption schemes provides secrecy in an effective manner. 1.5. Research Method Qualitative approach is appropriate for this research method. Qualitative Research Practice starts with the premise that one can improve their research skills by seeing what researchers actually do in particular projects and by adding their actions and plans into their own research practice. It actually demonstrates the benefits of using practical methods from real-life knowledge and will be necessary reading for anyone interested in the process of doing social research (Clive Seale, 2004). It is a field of inquiry that explains discipline and subject matters. It is called as ethnographic research. It involves collection of narrative data in a natural setting in order to gain insights into phenomenon of interest. This research studies many variables over an extensive period of time to find out the way things are, how and why they came to be that way and what it all means. Qualitative researchers do not want to interfere or control anything. The most common method of data collection i nvolves participant observation (Michael Huberman Matthew and Miles, 2002). Qualitative analysis offers a cluster of very useful procedures like guidelines, techniques etc. It actually refers to the educational issues and the understanding of learning and cognition (Pamela S. Maykut and Richard Morehouse, 1994). Hence, it can be said that the secondary data is preferred for this research while searching the related information to it as the other approaches cannot provide a better data to the research. Chapter 2: Literature Review 2.1. Overview Visual Cryptography is a particular encryption method used to hide information in images in such a way that it can be decrypted by the human visual system if the correct key image is applied. This method was suggested by Naor and Shamir in 1994. Visual Cryptography applies two transparent images. One image consist random pixels and the other image consist of the secret information. In visual cryptography it is not possible to recollect the secret information from one of the images. Both transparent images and layers are involved to reveal the information (Kiyoharu Aizawa, yuichi Nakamura and shichi satoh, 2004). The simplest method to implement Visual Cryptography is to bring out the two layers against a transparent sheet. When the random image contains genuinely random pixels then it can be seen as a onetime pad system and will offer infrangibly encryption. In visual cryptography pixel is divided into white and black blocks. In this chapter, importance of visual cryptography is disc ussed and a New Visual information Encryption Scheme is proposed followed by the explanation of Security analysis on images with the previous technologies. 2.2. Visual Cryptography Visual Cryptography refers to a secret sharing method that will encrypt the secret message into a number of shares and does not require any computer or calculations for decrypting the secret image rather the secret message will be reconstructed visually by overlaying the encrypted shares the secret image will become clearly visible. Visual cryptography scheme on a set P of n participants can be defined as a method of encoding the secret image into n shares so that the original image will be obtained by stacking specific combination of shares onto each other. Visual cryptography technique was initiated by the Naor and Shamiri at Eurocrypt 94. It is a process used for separating one image into various shares. Visual cryptography solutions functions on binary inputs. Visual cryptography is a special technique used to hide information in images in such a way that it can be decrypted by the human vision when the correct image is used. It uses two images one image contains secret informati on, in visual cryptography it is not possible to retrieve the secret information from one of the images, both transparent images are required to reveal the information. To print two layers into the transparent sheet is the simplest way to implement Visual cryptography (jeng shying pan, Hsiang cheh Huang and L. C. Jain, 2004). If the random image contains random pixel then it can be seen as a onetime pad system and will offer unbreakable encryption. These two layers slide over each other until they are correctly aligned where the hidden information appears. This type of visual cryptography which restores the image by stacking some significant images together is known as extended visual cryptography. Generally, visual cryptography suffers from the deterioration of image quality. The basic two cryptography models consists of a secret message encoded into two transparencies, one transparency representing the cipher text and the other acting as a secret key. Both transparencies appear to random dots when inspected individually and does not provide any information about the original clear text. By carefully aligning the transparencies the original message is reproduced (Borivoje Furht, Edin Muharemagic and Daniel socek, 2005). The original decoding is accomplished by the human visual system. Visual cryptography scheme is a visual secret sharing problem in which the secret message is viewed only in black and white pixels. Each pixel in the original image is represented by at least one sub pixel in each of the n transparencies or shares generated. Each share is comprised of collection of m black and white sub pixels where each collection represents a particular original pixel. The contrast of Visual Cryptography Scheme is the difference between the minimum number of black sub pixels in a reconstructed (secret) black pixel and the maximum number of black sub pixels in a reconstructed (secret) white pixel (Kiyoharu Aizawa, Yuchi Nakamura and Shinichi Satoh, 2004). The m ain instantiation of visual cryptographic realizes a cryptographic protocol called secret sharing. The important thing in secret sharing is it relies on a human visual system to perform the decryption. In a conventional secret sharing a secret shared among n participants can pull their shares and recover the secret but the subsets of the forbidden can obtain no information about that. Visual secret sharing schemes inherits all applications of conventional secret sharing schemes most notably access control. An example of the encoding of white and black pixels in a 2 out of 2 scheme can be seen in Figure 1. Here two shares out of the two generated would be needed to recover the original image. Since only two shares are generated, n = 2. White box represents a single white or black pixel in the original image. Sub pixel assignments that would be given to shares #1 and #2 respectively. The number of sub pixels per share used to represent the original pixel is four Finally, the overall visual effect when shares #1 and #2 are correctly aligned on top of one another. Notice that when the shares in this example are combined the original black pixel is viewed as black; however, the original white pixel takes on a grey scale. The structure obtained from either white or black pixel representation can be described by an n. Similar to the area of the secret sharing, more generally structures have been studied in the visual cryptography. The basic model of the visual cryptography consists of a sever al umber of transparency sheets. On each transparency a cipher text is printed which is identical from random noise. The hidden message is reconstructed by stacking a certain number of the transparencies and viewing them. The system can be used by anyone without any knowledge of cryptography and without performing any cryptographic computations. Naor and Shamir have developed the Visual Secret Sharing Scheme (VSSS) to implement this model [Naor95] (Mizuho Nakajima and Yasushi Yamaguchi, 2002). Thus, from the above discursion it can be stated that Visual cryptography is a special technique used to hide information in images in such a way that it can be decrypted by the human vision when the correct image is used. It is a simple and clear scheme that can partition the secret image into a number of shadow images and the dealers can distribute these shadow images to participants. The Visual cryptography scheme makes use of human visual system for recovering secret images by staking vari ous shadow images. 2.3. Importance of Visual Cryptography Visual Information system importantly elaborates the diligences scope of information systems and deals with the multimedia operating system which is supported by multimedia hardware and high bandwidth network. These are text oriented which provides reports, decision-making information and documents for all levels of hierarchy in the organization (Carlo Blundo and Stelvio, 2005). With the increase in multimedia platforms, visual information has become more available with the advancement of information technology; contact through internet has increased rapidly. Visual information system requires many kinds of facilities for effective visual information presentation and visualization. This system actually supplies inter related visual and multimedia information to support the operations, management and decision making functions in an organization. As internet can be accessed by everyone and anyone can easily access the information and transmit it without any protection there is possibil ity of grabbing the information as it became secondary data. So in order to avoid hacking of sensitive information, it should be encrypted before transmission (Yongfei Han, 1997). In order to protect the information Diffie and Helman (D-H) proposed a key agreement scheme that is implemented when two parties agree on a common session key. This key agreement also helps in improving the reusable process. This technique is utilized to calculate a common image for encryption and decryption with two parties. The D-H algorithm does not encrypt data or make a digital signature. This is exclusively used for the generation of shred secrets. The DH key agreement can be split into three parts; they are parameter generation that generates non secret public value and is expensive process, next is phase1generatres two key exchange values for the parties and phase2 is the originator and recipient that computes the functions in the given image. DH key agreement has a nice property that it is not sen sitive to off-line attacks but it is sensitive to man-in-the-middle attacks. There after Naor and Shamir proposed a methodology named visual secret sharing that provides secrecy to the information and avoids illegal activities (Jeng-Shyang Pan, Hsiang-Cheh Huang and L. C. Jain, 2004). This process is called as Visual Cryptography. This process provides secrecy by partitioning the secret digital image into several shadow images that are recovered by the human visual system by piling all those images together. It is secured technique where the data cannot be traced by others. In classic secret sharing, algorithms for splitting and sharing secret information are a stem of cryptography. In the most general case, their objective is to generate such parts for the data and that could be shared by multiple authorized persons. This problem of splitting information in a manner allowing its reconstruction by a certain n-person group interested in the reconstruction of the split information. Al gorithm solutions developed to achieve this objective and at the same time none of the groups of participants in such a protocol, whose number is lesser than the required m persons. It leads to opposing to read the split message. The algorithms for dividing information make it possible to split it into chunks known as shadows that are later distributed among the participants of the protocol. So that the shares of certain subsets of users collective together and these are capable of reconstructing the original information. There are two groups of algorithms for dividing information, namely, secret splitting and secret sharing. In the first technique, information is distributed among the participants of the protocol, and all the participants are required to put together their parts to have it reconstructed. A more universal method of splitting information is the latter method, i.e. secret sharing (Marek R. Ogiela and Urszula Ogiela, 2009). Thus, from the above discursion it can be sta ted that visual cryptography plays a vital role in securing the data and also in sharing the secret message as the data transferred through internet has been increased. rapidly. Advantages of visual cryptography Visual cryptography is simple to be implemented. Encryption incase of visual cryptography does not require any hard problem dependency. Specifically decryption algorithms are not required because a person aware of cryptography can easily decrypt the message. Cipher text can be Fax or e-mail in case of visual cryptography 2.4. Security analysis on images with the previous technologies The security analysis is the major aspect of the encryption. Analysis to the field of security will encounter the serious obstacle that deal is by nature not an exact science. The previous technologies which where there before the D-H key agreement encryption are manual encryption, transparent encryption, symmetric encryption and asymmetric encryption (Fedora Documentation Project, 2009). Visual cryptography can be seen as a one-time pad system. Then, it cannot be reused. Diffie and Hellman (D-H) key agreement method and Toral Automorphism (TA) such that visual cryptography can be reused. Both secret and symmetry-key are represented in binary image. The proposed scheme is simple and easy to be implemented for shadow images. Therefore, it can be used in many electronic business applications (Chao-Wen Chan and Yi-Da Wu, 2008). The Manual Encryption is a technique that will involve the use of encryption software. In this computer programs are used for encrypt various bits of information digitally. In this technique the encryption key is provided later in the process. The main security issues are the potential leakage through security insensible program and also the bad implementation may lead to re-encrypt with same key for same password (Bruice Schneier, 2007). Transparent Encryption is another type of computer software encryption. In this technique the data can be downloaded onto a computer to encrypt automatically. Every executable application and file created in the computer has an encrypted copy that can withstand power surges and protects information in case a computer is stolen. The security issues is the data which is automatically encrypted can be taken if the key provided is known (Cetin K. Koc, David Naccache and Christof Paar, 2001). The Symmetric Encryption is in which a letter or number coincides with another letter or number in the encryption code. This technique is commonly referred to as secret-key encryption. In this only single key is used for e ncrypting an

Short Story Example | Extreme Kidnap

Short Story Example | Extreme Kidnap Something clicked and my senses turned on; heart pounding, mind wide awake, fists ready for action as I started to hear the rush of wind and a propeller outside, a 12 seater Cessna Caravan. I could see two of my best friends with duct tape around their feet and seated at the back of the cabin next to the luggage compartment. I turned around towards the front of the plane. I could see blood on the ground; I felt the back of my head, and it was wet, sticky wet. I looked further past the blood. My eyes stung from the concentration, but I saw a man lounging on a red seat next to the aisle with a pistol pointed at me. I wiped my eyes to lessen the sting; it helped a little bit. I thought this was all a dream as I attempted to stand. I dragged a knee up, levering myself into vertical. I swayed as I looked at the mans face. It was dirty with red rings under his eyelids. His black hair was lank and greasy. He stood up and waved his gun towards the back of the plane. I continued to stagger to wards him, but something stopped me as I tried to take another step. I looked down to see my friend prostrate on the ground with his hand on my ankle. Tears were forming in his eyes. What was I doing? Im in a plane with people who have guns and two friends who have duct tape around their feet and I am walking towards my death? As I turned around, someone grabbed me from behind and forced me towards the back of the plane. Pain snaked across my upper arm and shoulder. My body was screaming out in agony as I tried to twist away, but all that happened was more pain. A blond haired man with a huge freckle of his chin forced me to sit with my back against the cargo door. Not too far away was the door that was used for exiting the plane. It had a simple red handled lever that was used to open the door. I glanced outside to see if there were any houses down on the ground but no, there was still only the Australian desert. From what I could see there were only small shrub bushes with occasional gum trees. There was no hope of escape. Another man appeared from the cabin carrying three items of baggage; they were a backpack of a sort. He approached us and calmly stated Thank you for being our experiment. We have some clients that want some fun with guns. They are placed on the ground and if they find you or see you they will shoot you. I began to panic. My heart was beating faster. As I looked across at my friends and they were trembling I began to realise what the backpacks were. They were parachutes. I told myself to remain strong and I gave my friends a reassuring pat on the shoulder. The blond haired freckle man spoke this time, Simple as this, you put on these backpacks and jump. I was shoved out the plane with barley enough time to put my parachute on. . It felt nice to be outside putting aside the fact that I was falling towards the ground at an astonishing rate. My lungs lurched out of their normal place right into my mouth, or so it felt like it. It was the biggest whoopsy I have ever had. I pulled the straps tight around me, and then I pulled the rip cord at the front. A small chute about the size of a kids plastic swimming pool opened up. My heart sank and I had the worst feeling in my life. I heard a tearing sound. I looked up and thought the mini-chute was tearing apart, but no, something forced its way out of the bag and pushed against my back. I saw a huge black object about the size of an Olympic swimming pool open up. I slowed down to a steady pace and all was calm, surprisingly. I scanned the sky for my friends, there was nothing except for the wispy white clouds and WHOA!! I exclaimed out aloud, as a large dark object whistled in front of me. It was Jake. I realised he didnt know how to open the chute. I screamed out, Pull the strings! It appeared that he didnt hear me, but after what seemed an eternity a parachute opened. I breathed a sigh of relief. I looked around, beneath, above and beside me. There was no one else, other than Jake, to be found. Could Frankie have fallen past me and crashed on the carpet of brown and green spots? I refused to belief that, and squinted my eyes to look across the sky where the plane was. I focused harder and thought I could see my friend. To confirm my thoughts a mushroom blew up in the sky. How on earth are Jake and I going to find Frankie now? Jake and I had levelled with each other in flight. As we neared the ground, which was about 50metres away, I tensed up for a hard landing. Jake glanced across at me, a nervous look on his face. I shouted out Aim for the clear patch and run when you hit the ground! Jake held up his hand and put his thumbs up. I looked up at the inside of the parachute to see if everything was fine, landing spot was okay, head still pounding but okay, legs sore and stiff; I was ready. In the last few seconds as I came down I started to run in mid air, Jake was doing the same. 4 metres, 3 metres, 2, 1, 0, SMASH, pain shot up my legs, but I continued to run. I slowed down, my parachute folding in on itself, scratches starting to bleed, dust blowing everywhere and legs collapsing under me. I lay there for a moment thinking over what had happened today or yesterday. Bike riding with my friends, kidnapped, drugged, woke up in a plane, forced to jump and now, apparently, prey in the middle of the Australian desert. I dragged myself up and dropped the parachute on the ground. I limped over to Jake who was lying face down on the dark red ground. Checking his breathing, I rolled him over. He had blood dripping out of a cut, just under his chin, but otherwise was okay. I went over to the parachute and tore a strip of fabric of it. As I wrapped the cloth under his chin and over his head, I had to chuckle a little bit. He looked a little like red riding hood. Jake sat up and said, I dont think I will ever do parachuting again in my life. Same here, I replied. I continued in a more serious manner, Okay lets move out, we have no idea how many people are trying to kill us and we have to find Frankie. We got up and began to walk away from the landing site, towards Frankie. The terrain was flat but it was not desirable. There were small knee height bushes covering every bit of land, we couldnt see the ground and I was afraid of being bitten by a snake. There were a few taller shrubs that were my height, but were sparsely spaced out. There were also a few gum trees that I could see in the distance and nothing else of importance. There was an eerie silence; there were no birds, cars engines, horns or people yelling. The silence was totally opposite to the sound of Perth, where I live. We continued our journey towards Frankies landing spot. Both of us had walked 2miles all ready. We came upon a gum tree, it was a large tree and it provided a lot of shade. We stopped and sat for a rest, my throat was dry as parchment and it hurt. My legs were also shaky from lack of food. The sun was getting hotter. It must be near midday I thought. All of a sudden we heard leaves rustling, Jake and I jumped into the nearest bush, because we thought it was someone with a gun. My heart pounded, and prickles went all over my body and started pressing into my skin. Out of the surrounding a voice yelled. Oi! up here. Sweat was pouring out of all my sweat glands, I lay down as flat as I could, it was uncomfortable and I was really scared. I couldnt see my friend and wished the best for him. Then the voice yelled out again, Help me Im stuck in this tree. I looked up without getting out of my hiding spot. In the gum tree I saw Frankie dangling with his parachute snagged on the higher branches. I crawled out of the bush, being careful not to cut myself again. I hoped to my feet and yelled in a happy voice, Frankie! Frankie yelled back, Of all the open shrub land I landed in a tree. I began to laugh and say, Well we landed in the only spot where it has clear ground. Jake came across to where I was standing and glared up and said, How are you going to get down? You are about 2 stories high, dangling in the air with no branches nearby. Frankie shouted back, Ill jump, but first Ill drop this down to you. He reached around and grabbed the zip on his bag and yanked it down, he pulled out a grey plastic shopping bag. He carefully dropped it to the ground; it went clunk and a crackle. I went over and picked the bag up, I glanced inside and there was three one litre mount Franklin bottles. I moved the bottles around and saw a flash of bright red; I reached in more and pulled out three big mars bars. About time I got some good news, I said aloud. Look at below said Frankie as he released the strap and jumped. He landed on the heavy side but was okay. We all sat down and pulled out the water bottles and had a drink. It felt nice, clean crisp cold water running down my dry throat. I had already drunk more than half of the water, but I stopped because we had to ration the water. We got up and walked west. According to Frankies watch by lining the hour hand with the sun, and halfway between the minute hand and the hour hand was north. Head for the ocean was our thinking. We walked for ages, my legs are sore and sweat is pouring out of my back. The terrain was changing there were more mounds in the dirt and uneven ground. There were more trees with greener leaves. While we were walking along taking sips of our water we came across a small gravel cliff. We all began to climb down, however I slipped on the gravel and tried to grab the nearest plants, but I ripped them out as I fell. I clawed my hands against the edge of the rock face, but I couldnt grab anything. I was increasing my speed; it was a 3 story building drop and I was approaching the bottom. I looked down it rounded of a little bit. It flashed through my head as if it were less than a second. I hit the bottom, my legs skidded out from the soft sloping gravel and I hit my head after my hands tried to lessen the impact. I cried out in pain as I yelled for my friends to help me. I lay on the ground with pain coming from my leg, ankle and head. I felt giddy and the world spun around me. Then a supporting hand lifted my head and propped me against a tree nearby. My friends came into view; there were tears in their eyes. I reached over to touch my leg which I couldnt feel. I couldnt see that well so I was going by touch. I ran my hand from my hip down to my knee, over the knee cap, halfway down my lower leg then I reached a bump in my leg, I continued to run my hand down but it wasnt just bent it was broken. It was lucky that I couldnt feel much pain because I would be crying out if I did.

John F. Kennedy and Abraham Lincoln Essay -- Compare Contrast Compari

John F. Kennedy and Abraham Lincoln Abraham Lincoln was the 16th President of the United States of America. He served as President when the country was under war. Abe Lincoln was born in 1806 and grew up in the countryside as a pioneer. His mother died at a young age and he had a sister. His father married a widow that had three children and Abe Lincoln liked her very much. Every day he attended school and worked very hard on his father's farm. John F. Kennedy was born in 1917 and died in 1963. John grew up in Massachusetts in a very wealthy and politically powerful family. His father was ambassador for Great Britain and his mother was the daughter to John F. Fitzgerald, who was a congressman and major of Boston. John Kennedy was a Harvard Graduate. He was the one in the family expected to accomplish great things. JFK has 3 children, John Jr., Caroline and Patrick. John Jr. died in a plane crash, while on his way to his brother Robert's daughter Cory's wedding. Patrick died when he was 6 weeks old while JFK was in office. Caroline is the only persona live in this family. JFK's brother Robert ran for President after him but was assassinated in 1968. He was the Attorney General before this. His other brother, Ted is now the U.S. Senator for Massachusetts and also his older brother Joe was killed in World War II, flying a plane. JFK was enlisted in the Navy during World War II and was awarded for being brave. AFter the war, he got a seat in Congress in a Boston district. When he was Senator, he won a Pulitzer Prize for his book Profiles in Courage. Kennedy was elected in 1960. While he was in office, he suffered back pain from injuries from the war. Kennedy was then assassinated in 1963. One of Lincoln's first opponents was Douglas, they were running for U.S. Senate. Douglas was a two-term Senator with a great background and Lincoln was self-educated and only had one term in Congress. The odds were stacked against Lincoln's "vast moral evil" of slavery, he started to make more Republicans like him, and they thought he would be great for the Presidency in 1860. Besides Lincoln who was running was J.C. Breckinridge (Southern Democrat). John Bell (Constitutional Union) and Stephen Douglas (Northern Democrat). Lincoln won the Presidency with 180 electoral votes and 1,865,593 popular votes. Lincoln was part of the republican party. At first, that part... ...ion's stand start to arise. Looking over the evidence the Warren Report is based upon leads to that, the Commission took great liberties in smoothing over contradictions in the information and failed to follow up on evidence suggesting that Oswald had confederates. As evidence came in, the Commission went with what it believe. OPINION I can only imagine how America felt in November 1963. John F. Kennedy created this era of optimism and hope. After he died his dreams he had set for our country went along with him. America was left with sorrow and despair. No one alive then had ever imagined that would happen, not to them, not to their country. I also feel that the CIA killed JFK , just from reading Earl Warren's report, and the JFK Records Act, because some evidence is still being held back from the public and no one really knows what happen from Parkland Hospital to the autopsy room at Bethesda Naval Hospital.Was Kennedy's nody played with? I believe so. Plus i also think that there was more than one shot fired at Kennedy after watching Abraham Zapruder flim because its almost impossible that one bullet went through Kennedy and still wounded John Connally in a few places.

Its Time to Stop the Censorship Music with Explicit Lyrics Essay

It's Time to Stop the Censorship Music with Explicit Lyrics Music with explicit lyrics or content started having black and white parental advisories on them in 1994 (http://www.riaa.org/Parents-Advisory-4.cfm). Are these labels necessary? Is controversial music molding our society and causing teenagers to turn to drugs? Is censorship necessary to protect the youth of our nation. Generally, younger people are against censorship on this issue. Music is an outlet and even an anti-drug for many teens; however, parents and society feel differently. Should parents censor their children or society, many parents would like to raise their own children. â€Å"Censorship, like charity should begin at home; but unlike charity, it should end there,† is a quote by Clare Boothe Luce (Fitzhenry, 84). Many believe that the â€Å"explicit† lyrics and content in this controversial music like Eminem will turn their children to crime and drugs. Music censorship started in the United States in the late fifties and continues till today. Will it ever go too far or stop? Society causes a lot of music censorship. Starting in the late fifties and early sixties members of society made efforts to censor R&B music(http://teenmusic.about.com/library/weekly/aa022301a.htm). They were concerned that the music endorsed wild living, promiscuous sex, and lewd dancing (http://teenmusic.about.com/library/weekly/aa022301a.htm). â€Å"During the late sixties and seventies, Jim Morrison’s dark and suggestive lyrics stirred up communities, and parents were appalled to see Elvis Presley’s hip-thrusting† (http://teenmusic.about.com/library/weekly/aa022301a.htm). Society censors music like this because they are afraid of it. They think it will alter the minds of their children and cause them to do things they would have never done if it were never suggested in a song’s lyrics. â€Å"Music mirrors the society that creates it† (http://teenmusic.about.com/library/weekly/aa022301a.htm). Some people believe this, while others believe that mu sic causes problems in our society such as crime and drugs. â€Å"For every person who believes certain lyrics portray a frightening world, there is another person who finds them deep and powerful because that world is all too real† (http://teenmusic.about.com/library/weekly/aa022301a.htm). A number of people believe there is a correlation between album sales and the parental adviso... ...ost, I believe that music censorship infringes our first amendment to the Constitution, freedom of speech. Saying that music artists may not use certain words is the same as saying a newspaper cannot print a certain article in my opinion. Yet it seems that music is an easier target because pro-censorship groups claim that they are helping the youth of America. Sources 1. â€Å"About R.O.C.† 11 February 2002. http://www.theroc.org/aboutroc/roc10.htm 2. â€Å"Controversial Music, The Beat Goes On.† 7 February 2002. http://teenmusic.about.com/library/weekly/aa022301a.htm 3. Fitzhenry, Robert I., ed. The Harper Book of Quotations. New York, New York: Harper Collins Publishers Inc., 1993. 4. Hoffman, Hank. â€Å"Wal-Mart Blues.† 18 February 2002. http://www.metroactive.com/papers/sonoma/01.09.97/walmart-music-9702.html 5. Record Industry Association of America. 7 February 2002. http://www.riaa.org/Parents-Advisory-4.cfm 6. â€Å"The 2 Live Crew.† 11 February 2002. http://music.lycos.com/artist/bio.asp?QW=2+Live+Crew&AN=The+2+Live+Crew&MID=66486&MH 7. Winfield, Betty Houchin and Davidson, Sandra, eds. Bleep! Censoring Rock and Rap Music. Wesport, Connecticut: Greenwood Press, 1999.

Main Essay

The Daily Mail quotes, â€Å"Protein drinks ‘are no help for athletes and aren't better than a balanced diet',† with The Independent also reporting that there is â€Å"no benefit from sports drinks†. However, does this affect the Protein sports drinks' market? Clear Barrett writes In an article on The Financial Times saying that Omnipotent. Com, Rupee's leading online sports nutrition retailer is forecast to generating earnings of EOM on annual turnover of MEME in the year 2011 from the sale of sports protein drinks and supplements, favored by bodybuilders and sports enthusiasts.Its sales are expected to reach EMMA this year. (Remuneration 2009) found that â€Å"Globally, the U. S is the largest market for sports nutrition supplements and represents 63% of the value. Mexico Is the second largest market with US $192 million In retail sales, followed closely by the united Kingdom with US SSL 72 million. Japan has a market size of US $87 million, while China and Ind ia have negligible sports nutrition retail sales. However, Authenticity and efficacy remain big challenges for the sports nutrition market. Remuneration, 2008) stated that â€Å"the global market for ports nutrition supplements was valued at US $4. 2 billion. The market experienced strong growth until 2008, then growth gradually declined due to a lack of consumer confidence In spending on discretionary products, as a result of the global recession. † Furthermore, recent research have Indicated that protein supplements are bad for your health and can be life threatening. The British Dietetic Association (BAD) says â€Å"high levels of additional protein can cause side-effects, which can include nausea as well as kidney and liver damage. The BAD argues there is now evidence to show excess levels of additional protein taken over a long time can cause health problems. Jane Griffin speaking for the BAD concluded, â€Å"People who have these high protein diets are now running Int o problems with their kidneys because of the amount of protein they must get rid of. † The information provided indicates that there was a decrease in demand in the market for sports protein drinks and can be conveyed in a supply and demand diagram. The first figure (1) is a rundown where value is determined by the market.The supply curve of a certain product as well as the demand curve of the same product is shown on the same axes. David King quotes â€Å"This Is where there Is no excess demand or excess supply, so that the quantity To summaries; â€Å"A demand curve shows the quantity that would be demanded at each price or wage, and a supply curve shows the quantity that would be supplied eat each price or wage. The price or wage will settle at its equilibrium level, which is the level at which the two curves intersect. † Figure (2) shows a shift in demand (to the left) for sports protein drinks.Because of the recession, globally protein drinks will be set at a pric e too high, even though the price does not change. Therefore, protein nutrition drinks will become less attractive for consumers, consequently forcing consumers to purchase less as the price is too high. A shift in the demand curve implies that the original demand curve has changed, meaning that the quantity demanded is affected by a factor other than price, in this case the global recession and awareness that protein drinks actually affect health and may be life threatening.To conclude, protein sports drink manufacturers would be forced to supply less for the same price. King quotes, â€Å"if demand decreases, buyers will demand a smaller annuity at each possible price. So the demand curve shifts left, and the equilibrium price or wage, quantity and expenditure all fall. † Price* Quantity* Price Quantity However, historically, the users of protein nutrition products have been limited to bodybuilders and athletes, but this has now expanded to include recreational users and li festyle users (Denominator 2006).Research in 2012 suggest that more teenagers are using muscle enhancing products, such as protein supplements, according to a study published in Pediatrics, a Journal of the American Academy of Pediatrics. A CNN article by (Trash Henry) quotes, â€Å"Researchers found the number of teens reporting muscle enhancing behavior to be substantially higher than in previous years. Boys were more likely to report these behaviors, which included supplement use and consumption of protein shakes†, while Dry.Maria Ginsberg, the lead study author said â€Å"These behaviors are a little more common among young Dry. Nicholas Fletcher, an assistant professor of orthopedic declares that, â€Å"As their idols have increased in size they are continually pushed to get stronger, bigger and faster†¦ There is that trickle-down effect. From this, we can assume that the market for Protein sports drinks is indeed rising, due to teenagers working towards increasin g their body mass and overall strength and striving to follow in the footsteps of their inspirational leaders.A BBC article done by Newsiest reporter (Kelsey) stated that Remuneration, whom researchers the market size of products, estimates that the sport supplement industry grew 15% last year. It estimated that one in five people who go to the gym more than twice a week use supplements that can come in the form of powders and bars. The information provided can assume that there is a cent increase in demand for sports protein drinks. Figure (3) below indicates that the quantity demanded for protein sports drink increased even though the price remained the same.A shift to the right for the demand curve depicts the quantity of demand for protein drinks rising. Again, a shift in the demand curve indicates that the original demand relationship has changed; meaning that quantity demand for protein sports drink is affected by something other than price. In this instance, demand for protei n was increased because of protein nutrition products expanding ND targeted not only athletes and bodybuilders, but also children and regular gym attendees. David King quotes, â€Å"If demand increases, buyers will demand a higher quantity at each possible price.So the demand curve shifts right, and the equilibrium price or wage, quantity and expenditure all rise. † To conclude, protein drinks will always be in demand as these products are used not only for sports use, but also widely used between regular gym attendees and children. However, the recent VAT increase implemented on sports nutrition drinks which has taken effect on the 1st October 2012 may cause the demand to slightly crease. References: King, D. (2012) Economics. POP Oxford Remuneration International. Lully 2009).

NPM in the Philippines

The sporadic but effective New Public Management practices in the Philippines as presented by the author may be good catalysts for NPM proliferation and actual practice, but as presented by Vina and Aceron in â€Å"Building the Basics†, the small sources of hope often die a natural death due to partisan politics, corruption and in my own opinion, in some areas, violence. The idea of managing the government like a business and treating citizens not as constituents but customers/clients, public administration is therefore mutating from a benefactor which people tend to thank for the service to as a service provider that the clients can claim their rightful service. The appointment of Secretary Robredo to the Department of the Interior and Local Government (DILG) is an effort of the Aquino Administration to have a successful grassroots-level performer and a paragon of good governance to effect change in the national level. I believe that the idea is for a veteran and proven NPM practitioner who understands the local scene can effect change. This strategy has been marred with recent unsavory criticisms of how he handled the DILG, e. g. the Quirino Grandstand Massacre. On Robredo, I believe a DILG Secretary should have a very strong grasp on a wide array of sectors, still, he has to focus on the sector that he is most effective, local administration. His weakness on the other sectors should be complemented by undersecretaries and assistant secretaries to present a competent multi-sectoral leadership. On the privatization efforts of Weihl, if the Philippines will continue to further privatize services, a very thorough study should be made to assure that these companies which will be placed in monopolizing positions, would not be able to abuse that position and further place the Filipino further down the poverty line, e. . Oil Deregulation and Energy Sector Privatization. Though majority of the bureaucracy and the private sector have lost hope in the moral recovery program of the government, I have not. A moral recovery program should go hand-in-hand with the headhunt for corrupt officials to expedite the change process in Philippine public administration. As the saying goes, if we want something we’ve never had before, we should be willing to do something we’ve never done before. †