Biblio

Image Encryption is a technique where an algorithm along with a set of characters called key encrypts the data into cipher text. The cipher text can be converted back into plaintext by decryption. This technique is employed for the security of data such that confidentiality, integrity and authenticity of data is maintained. In today's era security of information has become a crucial task, unauthorized access and use of data has become a noticeable issue. To provide the security required, there are several algorithms to suit the purposes. While the use and transferring of images has become easy and faster due to technological advancements especially wireless sensor network, image destruction and illegitimate use has become a potential threat. Different transfer mediums and various uses of images require different and appropriately suiting encryption approaches. Hence, in this paper we discuss the types of image encryption techniques. We have also discussed several encryption algorithms, their advantages and suitability.

Cryptography is the fascinating science that deals with constructing and destructing the secret codes. The evolving digitization in this modern era possesses cryptography as one of its backbones to perform the transactions with confidentiality and security wherever the authentication is required. With the modern technology that has evolved, the use of codes has exploded, enriching cryptology and empowering citizens. One of the most important things that encryption provides anyone using any kind of computing device is `privacy'. There is no way to have true privacy with strong security, the method with which we are dealing with is to make the cipher text more robust to be by-passed. In current work, the well known and renowned Caesar cipher and Rail fence cipher techniques are combined with a cross language cipher technique and the detailed comparative analysis amongst them is carried out. The simulations have been carried out on Eclipse Juno version IDE for executions and Java, an open source language has been used to implement these said techniques.

With the ever increasing growth of internet usage, ensuring high security for information has gained great importance, due to the several threats in the communication channels. Hence there is continuous research towards finding a suitable approach to ensure high security for the information. In recent decades, cryptography is being used extensively for providing security on the Internet although primarily used in the military and diplomatic communities. One such approach is the application of Chaos theory in cryptosystems. In this work, we have proposed the usage of combined multiple recursive generator (CMRG) for KEY generation based on a chaotic function to generate different multiple keys. It is seen that negligible difference in parameters of chaotic function generates completely different keys as well as cipher text. The main motive for developing the chaos based cryptosystem is to attain encryption that provides high security at comparatively higher speed but with lower complexity and cost over the conventional encryption algorithms.

Data sharing is a significant functionality in cloud storage. These cloud storage provider are answerable for keeping the data obtainable and available in addition to the physical environment protected and running. Here we can securely, efficiently, and flexibly share data with others in cloud storage. A new public-key cryptosystems is planned which create constant-size cipher texts such that efficient allocation of decryption rights for any set of cipher texts are achievable. The uniqueness means that one can aggregate any set of secret keys and make them as packed in as a single key, but encircling the power of all the keys being aggregated. This packed in aggregate key can be easily sent to others or be stored in a smart card with very restricted secure storage. In KAC, users encrypt a file with single key, that means every file have each file, also there will be aggregate keys for two or more files, which formed by using the tree structure. Through this, the user can share more files with a single key at a time.

The transmission of data over a common transmission media revolute the world of information sharing from personal desktop to cloud computing. But the risk of the information theft has increased in the same ratio by the third party working on the same channel. The risk can be avoided using the suitable encryption algorithm. Using the best suited algorithm the transmitted data will be encrypted before placing it on the common channel. Using the public key or the private key the encrypted data can be decrypted by the authenticated user. It will avoid the risk of information theft by the unauthenticated user. In this work we have proposed an encryption algorithm which uses the ASCII code to encrypt the plain text. The common key will be used by sender or receiver to encrypt and decrypt the text for secure communication.

Secure data communication is the most important and essential issue in the area of message transmission over the networks. Cryptography provides the way of making secure message for confidential message transfer. Cryptography is the process of transforming the sender's message to a secret format called cipher text that only intended receiver will get understand the meaning of the secret message. There are various cryptographic or DNA based encoding algorithms have been proposed in order to make secret message for communication. But all these proposed DNA based encryption algorithms are not secure enough to provide better security as compared with the today's security requirement. In this paper, we have proposed a technique of encryption that will enhance the message security. In this proposed algorithm, a new method of DNA based encryption with a strong key of 256 bit is used. Along with this big size key various other encoding tools are used as key in the encoding process of the message like random series of DNA bases, modified DNA bases coding. Moreover a new method of round key selection is also given in this paper to provide better security in the message. The cipher text contains the extra bit of information as similar with the DNA strands that will provide better and enhanced security against intruder's attack.