Cryptanalysis of a chaos-based encryption algorithm for distributed systems

Abstract

This paper analyses the security of a recently proposed chaos based cryptosystem. It shows that the cryptosystem under study has weak diffusion and presents a cryptanalysis that allows the attacker to decrypt any encrypted image. More precisely, it proposes a divide-and-conquer attack that allows an attacker to recover the internal states of the cryptosystem and to use them in order to encrypt or decrypt any image. Experimental results demonstrate the effectiveness of the attack and the lack of diffusion of the cryptosystem. Finally, a solution is proposed that can increment the security of the cryptosystem and render the cryptanalysis ineffective.