Cryptanalysis of a secure chaotic map based block cryptosystem with application to camera sensor networks

摘要

Recently, a block cryptosystem based on iterating a chaotic map is analyzed and improved. But still four security flaws in this improved cryptosystem have been identified with careful analysis. First, the first block of ciphertext is identical to the corresponding plaintext in special circumstances. Second, an important parameter can be obtained with a chosen ciphertext attack. Third, with this parameter, a known block of ciphertext, and the corresponding block of plaintext, a block of plaintext can be recovered by chosen ciphertext attack. Forth, the relationship between every two blocks of the keystream can be determined, leading to the recovery of the entire keystream if a single block of the keystream can be obtained. Those four security flaws render the cryptosystem insecure for general use.