Difference Timing Attack Against AES Based on Cache Timing Character

By analyzing the relationship between the indexes of array accesses and Cache hit or miss,weakly linear dependence between array indexes and its access time was found and verified with array accesses experiment.Based on analyzing the relationship between the indexes of the array accesses during general crypto implementation and the plaintext/ciphertext with the key,the Cache timing based timing difference analysis side channel attack is proposed.The experiment shows that with 4×104 samples,the search space of the sub-key used in the last round of the AES-128 can be reduced from 2128 to 298.