Statistical Analysis and Security Evaluation of Chaotic RC5-CBC Symmetric Key Block Cipher Algorithm

Abdessalem Abidi,Christophe Guyeux,Mohammed Bakiri,Anissa Sghaier,Mohsen Machhout

doi:10.14569/ijacsa.2019.0101070

Abstract

In some previous research works, it has been theoretically proven that RC5-CBC encryption algorithm behaves as a Devaney topological chaos dynamical system. This unpre-dictable behavior has been experimentally illustrated through such sensitivity tests analyses encompassing the avalanche effect phenomenon evaluation. In this paper, which is an extension of our previous work, we aim to prove that RC5 algorithm can guarantee a much better level of security and randomness while behaving chaotically, namely when embedded with CBC mode of encryption. To do this, we have began by evaluating the quality of such images encrypted under chaotic RC5-CBC symmetric key encryption algorithm. Then, we have presented the synthesis results of an hardware architecture that implements this chaotic algorithm in FPGA circuits.

Highlights

The main types of symmetric cryptosystems used nowadays fall into two broad categories: block cipher algorithms which consists of processing a data blocks of fixed size and the stream cipher algorithms operating on a continuous stream of data [19], [5]
We focus on the study of one of the most famous symmetric key block cipher algorithms, namely the Rivest Cipher 5 (RC5) [16]
The RC5 encryption algorithm is a symmetric key block cipher algorithm designed by Ronald Rivest of Massachusetts Institute of technology (MIT) and it first appeared in December 1994 [12], [1]

Summary

Introduction

The main types of symmetric cryptosystems used nowadays fall into two broad categories: block cipher algorithms which consists of processing a data blocks of fixed size and the stream cipher algorithms operating on a continuous stream of data [19], [5]. We focus on the study of one of the most famous symmetric key block cipher algorithms, namely the Rivest Cipher 5 (RC5) [16]. This encryption algorithm has been designed by Ronald Rivest and it first appeared in December 1994 [7]. Unlike DES [15] for instance, where the block size and the key size must be respectively 64 and 56 bits, in RC5, the block size, the number of rounds and the length of the secret key all can be of variable length This provides the opportunity for great flexibility in both performance characteristics and the level of security. The chaotic behavior of this algorithm has been theoretically proven according to the reputed definition of Devaney [9] and experimentally evaluated through sensitivity tests involving the avalanche effect phenomenon [2]

Objectives

Results

Conclusion