Cryptanalysis of a chaotic secure communication system

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

2001 IEEE International Conference on Acoustics, Speech, and Signal Processing. Proceedings (Cat. No.01CH37221)

Methods of attacking chaotic encryption algorithms have been developed. These methods have been applied to all the published chaotic encryption systems and all these systems are broken in very short computer times. Counter measures have also been developed in order to make chaotic encryption secure. Several examples and results are given.

Physics Letters A, 2008

Recently a chaotic cryptosystem based on discrete-time synchronization has been proposed. Some weaknesses of that new encryption system are addressed and exploited in order to successfully cryptanalyze the system.

This paper studies the security of a secure communication scheme based on two discrete-time intermittently-chaotic systems synchronized via a common random driving signal. Some security defects of the secure communication scheme are revealed: 1) the key space can be remarkably reduced; 2) the decryption is insensitive to the mismatch of the secret key; 3) the key-generation process used in this secure communication scheme is insecure against known/chosen-plaintext attacks. The first two defects mean that the secure communication scheme is not secure enough against brute-force attacks, and the third means that an attacker can easily break the cryptosystem by approximately estimating the secret key once he has a chance to access a fragment of the generated keystream. A direct result of the cryptanalysis given in this paper is the unsuitability of intermittent chaos in the design of secure chaotic cryptosystems.

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.

New generation communication networks are moving towards autonomous wireless infrastructures which are very popular in the application of multimedia broadcasting and mobile communication where N numbers of data are transfer through the wireless network every day. In such applications security of transmitted signal is very important in wireless communication network. So the proposed work creates a methodology to increase the security of the data and communication using chaotic encryption algorithm to transfer the data from the wireless network. A proposed new structure is based on coupling of chaotic system. We combine the text message with the chaotic signals to reduce the attack and improve the security of the data. The performance of BER in AWGN channel are verified and analyzed with MATLAB toolbox.

IEEE Transactions on Communications, 2003

This paper proposes a digital chaotic secure communication by introducing a concept of magnifying glass, which is used to enlarge and observe minor parameter mismatch so as to increase the sensitivity of the system. The encryption method is based on a one-time pad encryption scheme, where the random key sequence is replaced by a chaotic sequence generated via a Chua's circuit. In our system, we make use of an impulsive control strategy to synchronize two identical chaotic systems embedded in the encrypter and the decrypter, respectively. The lengths of impulsive intervals are piecewise constant and as a result, the security of the system is further improved. Moreover, with the given parameters of the chaotic system and the impulsive control law, an estimate of the synchronization time is derived. The proposed cryptosystem is shown to be very sensitive to parameter mismatch and hence the security of the chaotic secure communication system is greatly enhanced.

Information Technology And Control, 2015

The secure communication using synchronization between identical chaotic systems have been introduced in literature for a long time. A well-known practical application of chaotic synchronized systems is the Pecora and Carroll (P-C) secure communication method. In this paper, the P-C secure communication algorithm is applied to a novel three dimensional, autonomous chaotic attractor. Having a 45 ○ slope between sub-driver and subreceiver circuits of a novel chaotic attractor clearly demonstrates that it can be used for the purpose of secure communications.

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.

International Journal of Computer Science and Mobile Computing

A simple and easy to implement method of secret message cryptography will be introduced. The message to be encrypted-decrypted is to be converted to binary matrix, this matrix is to be reshaped to 16 columns matrix, and the contents of this matrix will be rearranged base on the contents of the generated indices key. A chaotic paramaters included in the private key will be used to run a chaotic logistic map model to generate a 16 elements chaotic key, this key will be sorted to get the required indices key. The proposed method will be flixeble and it will be used to encrypt-decrypt any message with any length. Changing the message or/and changing the key will not affect the method. The produced decrypted message will be sensitive to the selected PK, any changes in the private key in the decryption process will produce a carrupted unreadable message. The proposed method will be tested and implemented using various in sizes messages, the obtained result will be used to prove the sensit...