Search For High-order Differential In Plaintext Of AES Algorithm

For block ciphers,high-order differential and impossible differential are two of the most important analytical techniques.As one of the typical block cipher algorithms,AES is one of the most important techniques.In recent years,the differential attack on this algorithm is also a hot topic in cryptography research.Firstly,in the second chapter of this paper,starting from the mathematical basic knowledge of AES encryption algorithm and the overall structure of the algorithm,The aes algorithm is introduced in detail,and two important analysis techniques of block cipher are introduced in detail,that is,the high-order differential attack and the impossible differential attack,and the attack of these two technologies on the algorithm is also briefly introduced.In the third chapter,according to the encryption(decryption)of a AES algorithm,starting from the state matrix corresponding to the difference input in the differential divider,a certain number of bits are selected,and the corresponding plaintext differential feature search is carried out.In order to reduce the total complexity of cryptanalysis,some plaintexts are filtered out according to their characteristics,so as to reduce the data complexity of selecting plaintext.The fourth chapter is based on the fact that the Matlab software is active at the time of one and two bits in the computer,and makes a simple analysis of the test data,from the number of 0 in the difference,The approximate probability of the occurrence of the differential number in each differential case is calculated.Finally,the whole text is summarized,and the problem that the number of active bits in the state matrix is automatically searched by the computer and the software programming is solved,and a simple idea of the next step is put forward.