Analysis of Chaotic Stream Cipher OCMLE

This paper analyzes the chaotic stream cipher proposed in “Chaos-based secure communication in a large community”, it finds that the frontal values of the encryption sequence of the stream cipher are not sensitive to the least significant bits of the key. So the paper proposes divide-and-conquer attack with known plaintexts and analyses its success probability and complexity. At last, it presents the possible reformative measure of the cipher to its weakness and proves the validity of the measure.