Integral Cryptanalysis Of Lightweight Block Ciphers

Due to its special structure and fast encryption and decryption,block ciphers have always been the core algorithms for authentication and data encryption in the field of information security.With the development of Internet of Things,lightweight block ciphers have become a hot topic in cryptology research in the information age because of their low resource consumption and high efficiency.Security analysis of block ciphers has always been an important measure of the stre ngth of block cipher algorithms.Integral cryptanalysis is a kind of chosen plaintext attacks,after differential cryptanalysis and linear cryptanalysis,it is known as one of the most efficient attacks in the field of cryptology.MILP(Mixed Integer Linear Programming)is a method to divide the feasible region and then optimize the objective function in to obtain the optimal solution.The Division Property,which was proposed by Japanese cryptographer Todo in 2015,has become a hot issue in integral cryptanalysis.As a generalized integral property,it can construct a more effective distinguisher than the traditional integral cryptanalysis when analyzing the algorithm based on bit design.The MILP combined with the Bit-Division Property is also used to search for the lightweight block cipher algorithm for the integral distinguisher 's balance bit.The main contents of this paper is as follows: 1.After studying the security analysis method of the existing Midori64 algorithm,an integral attack on the Midori64 algorithm was proposed for the first time.By analyzing the structure of the Midori64 algorithm,a 4-round low-order integral distinguisher is first constructed,and then extended to 5-round of integral distinguisher in the direction of decryption on the basis of 4-round distinguisher.Used 5-round distinguisher to performed 6-round,7-round,8-round,and 9-round of integral attack,and give the corresponding time complexity and data complexity.2.Studied the generalized integral property Bit-DivisionProperty proposed by Todo,and then used the Bit-DivisionProperty combined MILP method to construct the MILP model for the round function of the Midori64 algorithm.Based on this,used the Python program to implement the automatic search of the Midori64 algorithm's integral distinguisher.The result verified that the manually specified Midori64 algorithm's integral distinguisher is correct.3.Studied the existing integral attacks on HEIGHT algorithm,and a new 17-round integral distinguisher of HEIGHT was b uilt with a different integral path.By using the 17-round distinguisher,25-round integral attack was proposed.After comparing and analyzing the keys,the number of keys that need to be guessed is finally obtained,and the key recovery is performed using the method of space sharing time,which reduces the time complexity.