SECURITY ANALYSIS OF FBDK BLOCK CIPHER FOR DIGITAL IMAGES

Abstract

Network security is one of the major concerns in th e modern world. In this regard, a strong security tis required to protect user data. Cryptography techniques plays an importa nt role in secured transmission through encryption of data and thus ensuring integrity, authenticity, confidentiality of informa tion. Several encryption algorithms have been propo sed like AES (Advanced Encryption Standard), DES (Data Encryption Standard ) and RSA. These provide very good encryption for t ext applications. However, these encryption schemes appear not to be ideal for image applications. Some algorithms like GKSBC and RC6 provide very goo d encryption for digital images. New techniques are ethat are aimed at providing secured transmi ssion of images over networks. The FBDK (Fixed Block with Dynamic Key Si ze) block cipher is a new cryptography technique de signed using simple operations like XOR, substitutions, circular shifti ng. The FBDK algorithm is applicable for blocks of any size with key size being dynamic for each block. It does not involve any com plex mathematical operations like modular exponenti ation. It is a hybrid cryptography technique based on symmetric key and akey cryptosystems. This paper investigate s the security of FBDK block cipher for digital images against brute-force attack, statistical analysis and Differential analysis attacks. In this paper, various security analysis tests has been discussed which ar e helpful in finding out whether the FBDK encryptio n algorithm can do secure encryption or not. Experimental results proves the security and efficiency of FBDK cipher for images against all aforementioned types of attacks which justifies its consideration for real time image applications.