On the Speed of Image Encryption with Chaotically Coupled Chaotic Maps

Pisarchik et al. presented an image encryption algorithm based on chaotically coupled chaotic maps. But G. Arroyo et al. found some flaws and security weaknesses in the proposed cryptosystem. In this letter, the speed of this chaotic cryptosystem is analyzed and the encryption speed claimed by the authors is argued. The maximum possible speed for the proposed algorithm is calculated analytically. Although it was claimed that, the chaotic cryptosystem is high-speed, our analysis shows that such a claim is not true.