Abstract
We have proposed a chaotic cryptographic scheme based on iterating the logistic map and updating the look-up table dynamically. However, it has been broken recently. In this paper, the weaknesses of the original dynamic look-up table scheme are analyzed and a more secure chaotic encryption scheme based on this dynamic look-up table concept is proposed. Theoretical analysis indicates that the modified scheme can resist the reported attacks. Moreover, simulation results show that this encryption scheme leads to a flat ciphertext distribution.