Abstract
Recently, Yen et al. presented a new chaos-based cryptosystem for multimedia transmission named “multimedia cryptography system” (MCS). No cryptanalytic results have been reported so far. This paper presents a differential attack to break MCS, which requires only seven chosen plaintexts. The complexity of the attack is O(N), where N is the size of plaintext. Experimental results are also given to show the real performance of the proposed attack.