On the Security of the Yi-Tan-Siew Chaotic Cipher

Title: On the Security of the Yi-Tan-Siew Chaotic Cipher

Research Question: Can the Yi-Tan-Siew chaotic cipher withstand cryptanalytic attacks? If not, what are its vulnerabilities?

Methodology: The researchers analyzed the Yi-Tan-Siew chaotic cipher using differential cryptanalysis, a technique that examines how small changes in the plaintext or ciphertext affect the resulting ciphertext or plaintext, respectively. They considered both chosen-plaintext and chosen-ciphertext attacks, assuming that the attacker can alter the time-stamp.

Results: The researchers found several security flaws in the cipher:

1. The sub-key K can be removed through differential chosen-plaintext and differential chosen-ciphertext attacks. This means that the claimed key (α, β, γ, K) collapses to (α, γ). 2. The sub-key β should not be part of the secret key because it does not contribute significantly to the cipher's security. 3. The noise vectors used in the encryption/decryption functions do not have a uniform distribution, limiting the value of the sub-key α and affecting the cipher's security. 4. The security of the cipher is independent of the chaotic map, but depends on a mixture of three operations from different algebraic groups.

Implications: These findings suggest that the Yi-Tan-Siew chaotic cipher is not as secure as previously thought. The researchers' attacks can be used to break the cipher and recover the secret key. Furthermore, the cipher's security does not depend on the chaotic map, but on other factors. This implies that other chaotic ciphers may also have similar vulnerabilities.

Link to Article: https://arxiv.org/abs/0402054v2 Authors: arXiv ID: 0402054v2