Cryptanalysis of a chaotic encryption system

Physics Letters A, 1999

We describe a computational procedure to encrypt a message, provided that the transmitter and the receiver dispose of identical, but otherwise not synchronized, chaotic dynamical systems. The technique is based upon the fact that the symbolic dynamics of these two systems can be used in order to sequentially construct data blocks which reproduce those from the input file. q

We describe a computational procedure to encrypt a message, provided that the transmitter and the receiver dispose of identical, but otherwise not synchronized, chaotic dynamical systems. The technique is based upon the fact that the symbolic dynamics of these two systems can be used in order to sequentially construct data blocks which reproduce those from the input file. q

Physics Letters A, 2003

In recent years, a growing number of cryptosystems based on chaos have been proposed, many of them fundamentally flawed by a lack of robustness and security. In this Letter, we explain how to break a very recent block cipher algorithm based on the logistic map. This cryptosystem uses a 128-bit external key to derive the initial condition and number of iterations, but in a weak way allowing for attack. As a consequence, the complete 128-bit external key can be obtained in a few steps. Using some weaknesses in the system parameter generation another attack can be used to recover the complete key.

Arxiv preprint arXiv: …, 2008

This paper analyzes the security of a recent cryptosystem based on the ergodicity property of chaotic maps. It is shown how to obtain the secret key using a chosen-ciphertext attack. Some other design weaknesses are also shown.

Physics Letters A, 2001

E. Alvarez et al. presented a new chaotic encryption approach recently. But soon G. Alvarez et al. broke it with four cryptanalytic methods and found some other weaknesses. In this letter we point out why the original scheme is so vulnerable to the proposed four attacks. The chief reasons are two essential defects existing in the original scheme. Based on such a fact, we present an improved encryption scheme to obtain higher security. The cryptographic properties of the improved scheme are studied theoretically and experimentally in detail.

Since 1980s, the idea of using digital chaotic systems to design new ciphers has attracted more and more attention. The use of chaos in cryptography depends on the natural relation between the two research areas: strong dynamical properties of chaotic systems implies strong cryptographical properties of cryptosystems, and the basic way to make cryptosystems have good strong cryptographical properties implies quasi-chaos (we even can find the phantom of chaos in Shanon's classic paper on theory of secrecy systems). Basically speaking, there are two paradigms of applying chaos for secure applications: analog chaotic secure communications (mainly based on chaos synchronization technique) and digital chaotic ciphers realized in computers. This dissertation only focuses on digital chaotic ciphers, i.e., the area lying between chaos theory and pure cryptography in finite-state (digital) world.

Journal of Sound and Vibration, 2004

An analysis of a recently proposed cryptosystem based on chaotic oscillators and feedback inversion is presented. It is shown how the cryptosystem can be broken when Duffing's oscillator is considered. Some implementation problems of the system are also discussed.

Chaos, Solitons & Fractals, 2005

This paper describes the security weakness of a recently proposed improved chaotic encryption method based on the modulation of a signal generated by a chaotic system with an appropriately chosen scalar signal. The aim of the improvement is to avoid the breaking of chaotic encryption schemes by means of the return map attack introduced by Pérez and Cerdeira. A method of attack based on taking the absolute value of the ciphertext is presented, that allows for the cancellation of the modulation scalar signal and the determination of some system parameters that play the role of system key. The proposed improved method is shown to be compromised without any knowledge of the chaotic system parameter values and even without knowing the transmitter structure.