SECURITY ANALYSIS OF FBDK BLOCK CIPHER FOR DIGITAL IMAGES

M. Kiran Reddy, K. J. Jegadish Kumar

Abstract: Network security is one of the major concerns in the modern world. In this regard, a strong security technique is required to protect user data. Cryptography techniques plays an important role in secured transmission through encryption of data and thus ensuring integrity, authenticity, confidentiality of information. Several encryption algorithms have been proposed like AES (Advanced Encryption Standard), DES (Data Encryption Standard) and RSA. These provide very good encryption for text applications. However, these encryption schemes appear not to be ideal for image applications. Some algorithms like GKSBC and RC6 provide very good encryption for digital images. New techniques are emerging that are aimed at providing secured transmission of images over networks. The FBDK (Fixed Block with Dynamic Key Size) block cipher is a new cryptography technique designed using simple operations like XOR, substitutions, circular shifting. The FBDK algorithm is applicable for blocks of any size with key size being dynamic for each block. It does not involve any complex mathematical operations like modular exponentiation. It is a hybrid cryptography technique based on symmetric key and asymmetric key cryptosystems. This paper investigates 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 are helpful in finding out whether the FBDK encryption 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.

Keywords: Cryptography, Ciphers, Encryption, Security, and cryptanalysis.

DOI: https://doi.org/10.15623/ijret.2014.0302068