演化密码对抗差分密码分析能力的研究
摘要
The evolutionary cryptosystem is a new cryptosystem. This paper studies its security level resisting against differential cryptanalysis. It is shown that the evolutionary cryptosystem possesses higher resistance than its initial fixed cryptosystem against differential cryptanalysis. On the basis of the relationship among the data complexity, the bit advantage and the success rate of differential cryptanalysis, it is proven that more data is needed for attacking the evolutionary cryptosystem when the bit advantage and success rate are identical. Moreover, it is shown that the time complexity for attacking the evolutionary cryptosystem is higher than that of differential attacking its initial fixed cryptosystem with the same amount of plaintext-ciphertext pairs. The research indicates that the evolutionary cryptosystem is more robust than its initial fixed cryptosystem against differential cryptanalysis.