Cryptanalysis of an ergodic chaotic cipher

Lessons Learnt from the Cryptanalysis of Chaos-Based Ciphers

“…The encryption procedure could be performed in different ways, but all of them demand the equiprobability of all the states contained in the pseudo-random sequences. If this requirement is not satisfied, then the conditional entropy of the ciphertext with respect to the plaintext may not be large enough so that some information will be leaked about relationships between the output and the input of the target cryptosystem (see the entropy attack in [11], and the cryptanalysis in [10]). This effect is specially significant for image encryption, as pointed out recently in [63].…”

“…This rule is not satisfied in the scenarios drawn by [31,34,20], partial knowledge of the key can be used to obtain the rest of the key [11,26,95].…”

Cryptanalysis of a discrete-time synchronous chaotic encryption system

“…However, many of the proposed schemes show important security weaknesses as a result of a bad or nonexistent key definition and bad or nonexistent key space specification [6][7][8][9][10][11][12][13][14].…”

A More Secure Chaotic Cryptographic Scheme Based on the Dynamic Look-Up Table

“…A number of attempts for the cryptanalysis of the original Baptista-type chaotic cryptosystem and its variants have been performed [2][3][4][8][9]. The first attempt was reported in [8].…”

“…Only one attack was proposed and it is in partial form. In the analysis made in [2], it was found that this type of chaotic cryptosystem actually behaves as a stream cipher although it operates like a block cipher that a fixed number of plaintext bits are encrypted to an integer number of iterations. Based on this observation, a keystream attack was applied to break the cryptosystem successfully.…”