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Cloud computing has emerged as a new technology that aims to provide unlimited virtualized resources to clients and enterprises. As services and huge sensitive data are being moved to the cloud server, a new challenge arises as to how to use the migrated data in a way that preserves privacy. Due to privacy concerns, important data should be encrypted before uploading onto cloud servers, so that only authenticated clients can access the data. Searchable encryption techniques allow the clients to search the encrypted data. Public key encryption with keyword search (PEKS) is a scheme of searchable encryption using a public key solution. In our scheme, we present a novel public key encryption with the ’fixed and short length’ keyword search which reduce the size of the keyword space and get keywords with a fixed and short length. Further, we employe the Bloom filters (BFs), which can accelerate the search process with a large amount of keywords. We also analyse the security of our construction in the random oracle model.

In the age of Information Technology Information Security is very important. To provide the security to the communication data, we are using different encryption algorithms. Encryption algorithms can be categorized into Symmetric key cryptography and Asymmetric key cryptography. Many of the Symmetric encryption algorithms (DES, 3DES, Blowfish, RC6 etc…) following the feistel structure, some algorithms (AES etc...) are following substitutions, permutations structure. These all are block ciphers. Symmetric Encryption Algorithms encrypting the plain text by using the secret key and producing cipher text. Decryption algorithms takes the cipher text and secret key and produces the original plain text, this is basically the encryption algorithm run in reverse. This paper specifies a new method for Symmetric key cryptography that can be used to protect data which is transferred through internet. This algorithm is not following the feistel structure, substitutions and permutations. This algorithm can be used for stream ciphers and block ciphers.

in data communication is a very important concern today. It is used in almost every region like e-commerce, education, and industry and data warehouse. Securely sending and receiving data in the above area is an important as the data is crucial. Image security plays an important role in this age. As the demand of image based message sending is improving day by day. In this paper, we have proposed an efficient image cryptography system based on RC6. The key size and number of variable rounds makes RC6 more secure. The key size is variable up to 2040 bits. The results are achieved in terms of entropy and correlation coefficients. The less variation in entropy is achieved from our approach. KeywordsChaos, Steganography, Security Measures. So in the ensuing segment we talk about data encryption method for picture encryption. We additionally talk about the pivotal angles which are utilized as a part of picture encryption with their points of interest and drawbacks. At long last taking into account the discourses we additionally recommend some future comment which may be productive in this bearing. There are niacumerous essential techniques which are second- hand pervasive cryptography, for example, private or mystery key cryptography, open fundamental or kilter, computerized mark, and hash capacities (15). In private key cryptography, a solitary key is leftover for both encryption and decoding. This obliges meander if all else fails part convey offering an impersonation of the key and the key be struck by be passed swear off a safe channel to the next individual (13-22). Private-key calculations are level indestructible and effectively actualized in equipment. Along these lines they are over and again second-hand for mass measurements encryption. The vast please of the all-around adjusted encryption rely on upon plaintext, encryption calculation, key and unscrambling calculation. The plaintext is the size ahead requiring the encryption calculation. It is joining of the inputs to the encryption calculation. The encryption calculation is the calculation used to continue on b deal with the information stranger plaintext to figure relieve. The mystery key is a comparable to repel of the encryption calculation and of the plaintext and it is associate of the encryption's inputs calculation (23)(24). The figure content is the defiant content discover as yield (14)(15). The steganography technique with cryptography will enhance the security as the cryptic content and the randomization quality can be improved.

Cloud security is the most critical task while considering its working environment, i.e. outsourced, distributed and utility based. In such cases making the users data confidential, increases the trust over the system. Also the security procedure does not make the availability affected in any ways. The users of these kind of systems is always retained the services and securities preliminaries with respect to the data itself. As the cloud user can access its data frequently and if here some encryption is used which requires decryption and the repetitive process continues to increase the overheads. It requires some mechanism in which encryption is performed and if the user requires to perform some operations on secure file without decrypting it can be fulfilled. Thus homomorphic encryption lets the user facilitates about the performing operations on encrypted data which reduces the complexity of confidentiality operations. Also to prevent Cloud Servers from being able to learn both the data file contents and user access privilege information used to generate key along with the fastest access of secured data by using Attribute-based encryption (ABE).

Data is any type of stored digital information. Security is about the protection of assets. Data security refers to protective digital privacy measures that are applied to prevent unauthorized access to computers, databases and websites. Cryptography is evergreen and developments. Cryptography protects users by providing functionality for the encryption of data and authentication of other users. Compression is the process of reducing the number of bits or bytes needed to represent a given set of data. It allows saving more data. The project aims to implement various cryptography algorithm for data security. The data will be first compressed using compression techniques and then encryption techniques will applied and then comparative analysis will be carried out for different combinations of compression and encryption techniques. If encryption and compression are done at the same time then it takes less processing time and more speed.

The growing requirement of system resources, memory requirement and huge space etc. have sprinted up the demand of cloud computing. The ease in the use and dynamic demand completion nature will also make it a future business platform. But we cannot forget the second side of the coin as the ease will comes with some negative cost. By the growing demand huge amount of data has been uploaded, update and shared. But data sharing and updating in the cloud environment may be risky. There are some trust mechanism should be there to secure the data. Our paper main motivation is to secure the sharing environment by sharing the data by the use of RC4 encryption and decryption mechanism. Then we have also detected the unauthorized data connection if there by our dynamic attack alert system.

years, security of several kinds of images is a major issue in secure data communication over any unreliable network. In this paper, a new technique to secure images by using grid-based encryption and decryption approach with RSA cryptosystem has been devised. This approach has taken original image, performed block transformation followed by grid transformation, then finally a public key cryptosystem is applied pixel-by-pixel to secure image. Experimental images have been taken and performed encryption and decryption to elaborate this technique. Error analysis shows that the technique is robust.

The main purpose of this work is the management of security. This will allow users authorization and integrity, accuracy and images security circulating on the Internet. Addition to that, more effort is required for an image-based data in the process of encrypting and decrypting the image. Proposed Architecture facilities for encrypting and decrypting an image using the suitable key and is designed to work for the same purpose. In this article we present a strategy for the new permutations based on a combination of different blocks of pixels and the symmetric encryption algorithm newly developed called "Image Symmetric Encryption Based on Block Displacement". The different blocks of the selected image is formed to change the layout of pixels into an image by the interchanging process, and then using the proposed symmetric encryption Algorithm the processed image will be encrypted. Keywords Encryption; Decryption; Security; Image, Cryptography; Algorithm.

The objective of this paper is to provide the dual level security for the key in playfair cipher using modified RSA digital signature scheme. This work has two phases, in the first phase the key is converted into the ASCII code and in the second phase, this work is using the concept of modified RSA digital signature scheme in which user authentication, data integrity and non-repudiation services are provided but as all know that in playfair technique, key exchange process is most important so there is a need to secure the key during key transfer that’s why this work is using the concept of modified RSA public key encryption technique to encrypt the key before sending it to the receiver for decryption. This work use a 10*8 matrix which contain all alphabetic in the uppercase as well as in lowercase, the numeric value from 0 to 9, list of operator and list of bracket. General Terms Key Security.

paper a number of image encryption algorithms based on chaotic maps has been proposed. Images are routinely used in diverse areas such as medical, military, science, engineering, art, entertainment, advertising, education as well as training. The fundamental issue of protecting the confidentiality, integrity as well as the authenticity of images has become a major concern. Most of the available encryption algorithms are used for text data. However, due to large data size and real time requirement, the algorithms that are appropriate for textual data may not be suitable for multimedia data. Some cryptographic algorithms such as RSA, DES and AES are not sufficient for image encryption. We try to implement Image encryption using S-DES (Simplified Data Encryption Standard). In preceding work, most researchers used to make a image using a key and then encrypt the chaotic image using the same key, but in this paper first make a chaotic map of the image using S-DES. Then use that chaotic image as a key for encrypting the image using S-DES. Thus in this paper select the key when encrypt the image and use a chaotic image as a key not any other text. Thus the encryption speed is some faster in this implementation as compare to previous work. S-DES is the reduced algorithm of DES. DES uses a well-known block cipher; it adopts Fiestel structure to iterate. The key Quantities achieve 56 bits, using the only key in an encryption is not safe obviously. Therefore a new approach has been proposed named as S-DES, which also adopts Fiestel structure. Combining the chaotic map with S-DES system can enhance the security of system by using the characteristic of sensibility of original value and randomness in chaotic map. Thus the encryption speed is fast in this implementation as compare to previous work.

Inside a dispersed foriegn atmosphere, anyone receives a untrusted company which has a change for better crucial allowing this foriegn to turn any kind of ABE ciphertext fulfilled through the wearer's features. Stability of ABE technique with outsourced decryption makes certain that a foe (including any destructive cloud) aren't going to be capable to study everything about the encrypted meaning. Anyway, this product doesn't ensure this correctness with the change for better completed through the foriegn. Verifiability ensures if thez change for better offers transpired appropriately or maybe certainly not. With this paper, it all recommend a improvised version of ABE with verifiability. A new concrete scheme pertaining to ABE with verifiable outsourced decryption can be recommended which is both safe along with verifiable without having based after hit-or-miss oracles.

In this paper ‘EDES (Enhanced Data Encryption Standard) using variable size key (128n bits) and 96bit sub-key’, we are providing a solution for an efficient and enhanced encryption for DES (Data Encryption Standard) to send encrypted information or file using more secure key and less time for encryption. Here, we present, design and implementation features of a proposed system EDES to be used for communication with secure information and file in the network.

The Cloud Computing is the next generation platform that provides dynamic resources pools, virtualization, and high availableness. Today, with the assistance of those computing, we are able to utilize ascendable, distributed computing environments among the boundary of the web, It provides several edges in terms of low value and accessibility of information, conjointly offers associate degree innovative business model for organizations to adopt It’s services while not forthright investment. Except for these potential gains achieved from the cloud computing, there are plenty of security problems and challenges related to it and conjointly knowledge privacy protection and knowledge retrieval management is one in all the foremost difficult analysis add cloud computing. To supply security a range of cryptography algorithms and mechanisms are used. Several researchers opt for the simplest they found and use it numerous combinations to supply security to the information in cloud. In this paper, we’ve got planned to form use of Digital signature and Kerberos with Advanced Encryption Standard cryptography (AES) algorithm program to guard Authentication, Confidentiality, and Integrity of information hold on in cloud.

Homomorphic encryption is the encryption scheme which means the operations on the encrypted data. Homomorphic encryption can be applied in any system by using various public key algorithms. When the data is transferred to the public area, there are many encryption algorithms to secure the operations and the storage of the data. But to process data located on remote server and to preserve privacy, homomorphic encryption is useful that allows the operations on the cipher text, which can provide the same results after calculations as the working directly on the raw data. In this paper, the main focus is on public key cryptographic algorithms based on homomorphic encryption scheme for preserving security. The case study on various principles and properties of homomorphic encryption is given and then various homomorphic algorithms using asymmetric key systems such as RSA, ElGamal, Paillier algorithms as well as various homomorphic encryption schemes such as BrakerskiGentry-Vaikuntanathan (BGV), Enhanced homomorphic Cryptosystem (EHC), Algebra homomorphic encryption scheme based on updated ElGamal (AHEE), Non-interactive exponential homomorphic encryption scheme (NEHE) are investigated.

security and encryption speed are two important aspects of image encryption algorithms. Due to their increasingly large size, video images present a great challenge to currently available cryptographic algorithms; the processes of encryption and decryption of images are so computationally intensive that they introduce delays beyond acceptable real-time application limits. (1) In this paper we introduce a new algorithm that uses dynamic square matrices as both encryption keys and the control stream to verify which key will be used for each block. The study case showed in this paper works on GF(7) and for encryption key sizes varying from 3X3 to 12X12 The goal is to provide a highly secure encryption algorithm with a wide space for encryption speed.

the worldwide activities of various organizations, enterprises and institutions, general agencies and individuals are done through Internet. The fast evolution of digital data exchange, security information becomes much important in data storage and transmission. The dramatic increase of data theft is a concern for the Internet community as a whole. Cryptography allows people to carry over the confidence found in the data transaction electronic world; Everyday thousands of people interact electronically, whether it is through e-mail, e- commerce, E-banking or overall data transformation using Internet. The perpetual increase of information transmitted electronically has led to an increased reliance on cryptography. Advanced Encryption Standard algorithm provides high security to information on networks. Further secure key mixing based Advanced Encryption Standard (KAES) algorithm is proposed by modifying the classical Advanced Encryption Standard algorithm. This algorithm is based on secure keys of 12 digit numeric key (Mobile Number). KAES algorithm using shift rows are cyclically shifted random generation values based and create new password sent to communicators mobile. KAES algorithms ensure the improved encryption performance, high secure and less encryption, decryption time. KAES algorithm is highly secure while improving the efficiency of cryptography algorithms. Keywordkey, Standard Encryption algorithm, Data security, Data

Ecash is a concept of electronic cash which would allow users to carry money in form of digital coins. Transaction can be done both offline and online in absence of a third party/financial institution. This paper proposes an offline model which supports multiple usage of transferable ecoin. The protocol is based on RSA, digital signature and a two-step encryption process. In this two step encryption, the user account details are encrypted in the coin using unique numbers in each step. The first encryption takes place during the successful receipt of the coin, where a receive end number is used for encryption,which is unique for every receipt. The second step of encryption takes place during successful spending of the coin,where a spending end receive number is used for encryption, which is unique for every spending of the coin. These two unique numbers comprise the major part of encryption in this model, prevents double spending and preserves user anonymity.

With the rapid growing of internet, information security becomes significant to protect secret and personal data. Encryption algorithm plays an important role for data security. In this paper, authors have evaluated the performance of two symmetric key encryption algorithms: BEST and NJJSAA used for data encryption and Analysed the encryption security, evaluated encryption speed for both algorithms. Experimental results show that BEST algorithm runs faster than NJJSAA algorithm while NJJSAA provide more security than BEST on the basis of Avalanche Effect.

Security has become an increasingly important feature with the growth of electronic communication. The Symmetric in which the same key value is used in both the encryption and decryption calculations are becoming more popular. The AES algorithm is capable of using cryptographic keys of 128, 192, and 256 bits to encrypt and decrypt data in blocks of 128 bits. This standard is based on the Rijndael algorithm. Here this paper presents the shared architectures for both encryption and decryption. Shared architecture reduces the area as well as the path delay. This methodology uses VHDL implementation of all the modules and results are concluded in terms of Delay and Frequency.

Encryption is the process of scrambling a message so that only the intended recipient can read it. Encryption can provide a means of securing information. As more and more information is stored on computers or communicated via computers, the need to insure that this information is invulnerable to snooping and/or tampering becomes more relevant. With the fast progression of digital data exchange in electronic way, Information Security is becoming much more important in data storage and transmission. Information Confidentiality has a prominent significance in the study of ethics, law and most recently in Information Systems. With the evolution of human intelligence, the art of cryptography has become more complex in order to make information more secure. Arrays of Encryption systems are being deployed in the world of Information Systems by various organizations. In this paper, a survey of various Encryption Algorithms is presented. General Terms Information Security, Encryption

The digital rights management (DRM) techniques are very important in the fields of multimedia security. The major areas of multimedia data security includes secrecy, ownership protection and traitor tracing. Even though, a number of encryption techniques were developed for multimedia encryption, most of them are vulnerable to several types of attacks. Hence, an encryption system having better security with minimal level of system complexity is an important requirement in multimedia security. In this paper, the cryptanalysis of two arithmetic coding based encryption techniques (randomized arithmetic coding(RAC) and chaotic binary arithmetic coding(CBAC))were proposed and proved that these schemes are vulnerable to known-plaintext attack. Then, a modified secure arithmetic coding based encryption system by providing block-wise shuffling of DCT matrix prior to the CBAC stage (block-shuffled CBAC)is proposed to improve the overall security of the system. In order to provide content protection after decryption for the proposed scheme, the joint fingerprinting and decryption (JFD) technique is provided at the receiver stage. Finally, this idea of image encryption has been extended to video (H.264 coding standard). Here, the work is based on a correlation preserving sorting algorithm whereby a comparable compression performance is obtained in addition to the high level of security. The proposed systems are tested against various types of attacks and it has been proved that these methods are able to withstand various types of attacks with good compression performance and minimal level of increase in system complexity.

ABSTARCTFastDES algorithm is based on Data Encryption Standard (DES). In FastDES, the one round function concept of DES are used in three different customs to produce a new fast and more efficient secure algorithm. The DES operates on half of the input data, 32-bit of chunk out of 64 bits, while FastDES take block of 32-bit and work on it simultaneously. The encryption start from 32-bit of data and 32-bit of key bits, which passes from three consecutive rounds and 32-bit of cipher is produce. This algorithm is fast, so it can be used in many further securities mechanisms like Hash functions (MD5, SHA series, HMAC) and modes of the operation like CBC, CFB etc. Because of its fast operations it is also recommended to use with other security applications. The DES round function provide a best confusion-diffusion structure of Substitution-Permutation Network (SPN). The FastDES based on same design criteria of S-boxes and permutation functions of DES. Like 3-DES with two keys and 3-DES with three keys, the FastDES can use 3-FastDES with 2 different keys and 3-FastDES with 3 different keys, which not only enhanced system security but also thwart the cryptanalysis for brute force and meet in meddle attacks.

Security is a basic requirement of an organization in the world to keep their information secure from their competitors. AES is the most recent algorithm which includes encryption with the help of reliable keys. It is used to protect the data including banking, financial, and government information. In this paper we analyzed various parameters of encryption techniques/algorithm. We encrypt the plain text by using different key size 128,192 and 256. On the basis of encryption time, other parameters can be determined e.g. processing time, round time, throughput etc. It is investigated that if clock frequency increases the throughput also varies.

threats such as viruses, worms, trojans and spyware affects the security and authentication of software codes, forcing software developers to build security schemes for better software protection. These software threats exploit the authenticated data of the software and confidentiality, integrity and accessibility is greatly affected by these software threats. A number of code security techniques like tamper resistant packaging, code obfuscation, register encoding etc have been developed which mainly concentrates on providing solutions for a particular type of threats and are vulnerable to code tampering and code injection by complicated attackers. Hence, code encryption technique has become an active area of research. This paper proposes a novel software protection code encryption scheme based on the index table. This approach uses a novel and efficient encryption technique called quasigroup encryption for encryption the indexed table. It provides least resemblance of the original data when encrypted. But, quasi group encryption is not efficient in diffusing the statistics of the plain text. This drawback can be overcome by using transforms. Hence, this approach uses chained Hadamard transforms and Number Theoretic Transforms to introduce diffusion along with the quasigroup transformation. The proposed approach is compared with the other encryption approaches and is observed to provide better results.

“Encryption is the primary solution to provide security to the data, which is travelling on a communication link between any pair of nodes, but Selective encryption is a technique to save computational power, overhead, speed, time and to provide quick security by only encrypting a selected portion of a bit stream. Securing the visual and multimedia data like images requires specific design consideration for use in different applications. The focus of this paper is on selecting the important part of the image that can efficiently achieve by conceptually selecting the part of the image which is further used in its normal mode of operation for encryption. Once encryption is done, the encrypted data is sent along with remaining original part of the message, ensuring its secured transmission and distribution over public networks.. This paper proposes a new approach for image encryption using matrix or grid conversion of image. The main idea behind the present work is to select the part of the image by the arranging the bit stream in grid form and choosing the diagonal of the grid. The issue in traditional cryptosystem in many different areas such as wireless networking, mobile phone services and applications in homeland security is energy consumption for encryption of the large volume visual data. So we are dealing with a partial encryption algorithm of images.”

The present paper is an extension of the previous work of the authors i.e. UES version-II and III. Roy et al recently developed few efficient encryption methods such as UES version-I, Modified UES-I, UES version-II, UES version-III. Nath et al developed some methods such as TTJSA, TTSJA and DJMNA which are most suitable methods to encrypt password or any small message. The introduction of multiple feedbacks in TTJSA and TTSJA it was found that the methods were free from any brute force attack or differential attack or simple plain text attack. The authors proposed the present method i.e. Ultra Encryption Standard Version-IV. It is a Symmetric key Cryptosystem which includes multiple encryption, bit-wise reshuffling method and bit-wise columnar transposition method. In the present work the authors have performed the encryption process at the bit-level to achieve greater strength of encryption. In the result section the spectral analysis is done on repeated characters. The authors proposed method i.e. UES-IV can be used to encrypt short message, password or any confidential key.

security is an important issue in data transmission through any type of network whether it is LAN, WAN, MAN or PAN. We are concentrating on PAN that is personal area network. Bluetooth is an example of this type of network. To provide the security in Bluetooth communication currently used encryption algorithm is a 128 bit symmetric stream cipher but symmetric cipher may be broken under certain condition. Another popularly used encryption algorithm for Bluetooth security are Data Encryption Standard (DES) and Ron Rivest, Adi Shamir and leonard adleman (RSA) Algorithm. However DES is vulnerable to possible attacks. To overcome these limitations and increase the security in Bluetooth communication here we propose an integrated cryptographic scheme. This scheme is based on Triple DES, RSA and MD5.Triple DES algorithm (variant of DES) is used for encryption, which is more secure in comparison to DES. RSA is used to encrypt the key of triple DES. Message digest Algorithm MD5 is adopted in this mechanism to verify the integrity of the message. Three major security principles such as authentication, confidentiality and integrity are achieved together using this scheme.

File is a collection of information that computer uses. The information is sensitive part of the organization. Any loss or threat to information can prove to be great loss to the organization as well to people. There are various means to protect the files from various threats. This paper describes various symmetric algorithms like Advanced Encryption Standard (AES), Blowfish, and DESX, a stronger variation of Data Encryption Standard (DES) to protect various types of files such as EXE, DOC, WMV and AVI files. The comparison of these algorithms is done in terms of Encryption and Decryption Throughput.

Encryption algorithm plays a crucial role in information security which guarantees the recent growing internet and network applications. They are used to secure the data in wireless networks against malicious attacks but securing data also consumes resources such as C.P.U time, Memory, battery power, encryption time etc. In this paper, we evaluated the performance of four symmetric key encryption algorithms; AES, DES, 3DES and Blowfish which commonly used for data encryption in terms of encryption time, decryption time & throughput. In this research, we evaluated encryption time, decryption time and throughput for all four encryption algorithms in Visual Basic’s environment using large size text data (.doc). Experimental results show that Blowfish encryption algorithm may be more suitable for wireless networks. Study reveals that Blowfish gives better performance than AES, DES and 3DES in terms of encryption time, decryption time & throughput.

Computing is becoming next stage platform in the evolution of the internet. It provides the customer an enhanced and efficient way to store data in the cloud with different range of capabilities and applications. The data in the cloud is stored by the service provider. Service provider capable and having a technique to protect their client data to ensure security and to prevent the data from discloser by unauthorized users. This paper, will gives a descriptive knowledge regarding cloud computing privacy and security issue provided by encryption and decryption services. If a cloud system is performing a task of storage of data and encryption and decryption of data on the same cloud then there are much more chances of getting access to the confidential data without authorization. This increases the risk factor in terms of security and privacy. This paper helps us on proposes a business model for cloud computing which focused on separating the encryption and decryption service, from the storage service provided by service provider. I means that both encryption and decryption of the data can performed at two distinct places. For studying this proposal are using a business model named as CRM (customer relationship model) for an example. For the evaluation of effective an efficient technique of data storage and retrieval we are providing three clouds separately such as including encryption and decryption services, secondly storage and a CRM application system. In this Research paper, we have tried to access separate encryption and decryption service using RSA algorithm and computing is a paradigm in which information is stored in servers on the internet. That information retrieved by the client as per usage. For this manner, we provide us a solution for data security, confidentiality and privacy based on a concept of separate encryption and decryption service. Keywordscomputing; encryption and decryption cloud service; service level agreement; availability; reliability; integrity; data privacy protection

Encryption is of prime importance when confidential data is transmitted over the network. Varied encryption algorithms like AES, DES, RC4 and others are available for the same. The most widely accepted algorithm is AES algorithm. We have proposed a new algorithm based on the concept used by Rijmen and Daemen (Rijndael algorithm), the founders of AES algorithm. The proposed algorithm encrypts and decrypts two 128 bits data simultaneously i.e. 256 bits data, thus providing strong encryption accompanied with complex processing. The proposed Feistal algorithm uses various invertible, self-invertible, and non-invertible components of modern encryption ciphers and key generation same as that of AES. This algorithm provides a secure, fast, and strong encryption of the data. There is a huge amount of confusion and diffusion of the data during encryption which makes it very difficult for an attacker to interpret the encryption pattern and the plain text form of the encrypted data. The proposed algorithm is also resistant to Brute-Force and pattern attacks.

weak point of the existing block encryption scheme is that the plain text or encryption key could be easily exposed differential cryptanalysis or linear cryptanalysis, which is mostly used for decoding block encryption. This is because the encryption schemes have been designed for the fixed size encryption key. Another weak point of the existing block encryption algorithm is that it has a fixed permutation table and fixed number of encryption rounds. In order to overcome these weaknesses, an encryption algorithm using unlimited size of key and dynamically changing permutation table should be designed. A new encryption technique called Variable size Block Encryption using Dynamic-key Mechanism (VBEDM), which is designed with unlimited key size, dynamically changing permutation table based on the encryption key and variable block size for each round. To make the cryptanalyst hard to expose the plain text, from the array of compression algorithms the VBEDM uses a compression technique based on key. The compression used is not for compressing the text but for strengthening the encryption method. Because of its dynamic functionality in input block size, key size, permutation, number of rounds and compression it makes the crypt analyst too hard to analyzing the cipher text. This algorithm also uses a compression technique from an array of compression algorithm resulting in more confusion to the analyst.

encryption algorithm (3,12,16) was examined based on the text to be encrypted and the chosen key. It is a symmetric key algorithm and uses stream cipher i.e. data is being encrypted bit by bit. The same algorithm is used for both encryption and decryption. The data stream is XORed with the generated key sequence and the key stream is completely independent of the plaintext used. The weakness of the algorithm has been found out and is being rectified. We proposed a modification in RC4 algorithm that would result in saving the memory space and also augment the performance by reducing the time. The proposed algorithm explains that we can have the key as an image so that we can compress it and store. Hence the algorithm yields better results in hardware also.

This paper introduces a model for information security and message hiding based on image steganography as well as it describes about various steps of that proposed model in brief. Keywords-Image steganography, Data Hiding

Encryption and watermarking are two primary and complementary technologies for protecting multimedia content. In this paper, we present a hybrid image protection scheme to establish a robust content-based authentication by using novel cryptosystem based on matrix transformation for generation of encryption key and copyright protection by using SVD based watermarking system. This paper suggests efficient method for encryption of image by self-invertible matrix with Hill Cipher algorithm. The Hill cipher algorithm is a symmetric cryptosystem for data encryption but cannot encrypt images. The novel cryptosystem uses randomly generated self-invertible matrix as an encryption key for each block encryption of an image and finding inverse of the matrix while decryption. This method having less computational complexity, because the inverse of the matrix is not required for decryption. For watermarking, we use SVD concept to provide a removable watermarking scheme for content based watermarking. The proposed scheme modifies the embedding strategy of SVD scheme. The proposed scheme yields higher security with superior encryption and robust to common image processing distortions. Experimental results show the effectiveness of the proposed hybrid scheme.

In this paper, design and FPGA (Field Programmable Gate Array) implementation of embedded system for time based IDEA encryption is presented. Presently available encryption systems, suffer from Brute Force attack in which all key combinations are tried out to find the correct key. In such a case, the time taken for breaking the code depends on the system used for cryptanalysis. In the proposed system, time is used as a second dimension of the key. That is, the correct key entered at the correct time is needed for proper decryption. The proposed scheme uses a dynamically varying number of shifts for both encryption and decryption thereby the system needs to wait till that time and this forms the time based key input. Hence, the possibility of brute force attack is minimized and is free from the system capability. IDEA encryption algorithm is taken as the base and time factor is implemented as a second dimension of the key. The proposed system adds complexity to the IDEA encryption algorithm by including the time as a second dimension besides increasing the time required for cryptanalysis. As the proposed system needs concurrent execution and real time processing, the system is implemented using Altera Stratix III FPGA and the results are presented.

In current day scenario, the need to protect information has become very important and hence the need for cryptographic algorithms is high. Here, we extend the parallel key encryption algorithm and bring out its full potential by implementing the various cryptographic modes such as cipher block chaining and interleaved cipher block chaining where commendable increase in efficiency and reduction in encryption and decryption time can be seen. We have also considerably increased the key size by using 1024 bit and 2048 bit keys for the algorithmic implementation and in CBC and interleaved CBC execution. Our practical analysis has brought to front the salient features of the parallel key encryption algorithm and its ability to provide enhanced data protection when using a larger key size along with its randomness property. In theoretical analysis, it can be shown that remarkable reduction in encryption and decryption time of cryptographic systems is achieved and an enhanced strength to the system against brute force attacks is achieved. Furthermore, PCA can be extended for different cryptographic modes, using varying key size and number of keys used in the process.

Elliptic Curve Cryptography (ECC) fits well for an efficient and secure encryption scheme. It is efficient than the ubiquitous RSA based schemes because ECC utilizes smaller key sizes for equivalent security. This feature of ECC enables it to be applied to Wireless networks where there are constraints related to memory and computational power. The goal of this research is to develop an efficient method for Scalar Multiplication and to develop simple and efficient encryption scheme. In this paper we have compared the security of Elliptic curve AES (ECAES) with the Encryption scheme proposed by us. A comparative study of ECC with RSA is made in terms of key size, computational power, size of data files and encrypted files.

This paper presents the architecture and modeling of RSA public key encryption/decryption systems. It supports multiple key sizes like 128 bits, 256 bits, 512 bits. Therefore it can easily be fit into the different systems requiring different levels of security. In this paper simple shift and add algorithm is used to implement the blocks. It makes the processing time faster and used comparatively smaller amount of space in the FPGA due to its reusability. Each block is coded with Very High Speed Integrated Circuit Hardware Description Language. The VHDL code is synthesized and simulated using Xilinx-ISE 10.1. It is verified that this architecture support multiple key of 128bits, 256bits, and 512 bits. General Terms Security, Algorithms, Cryptography.