Security Analysis Of Lightweight Block Cipher RAIN

Lightweight block cipher is an important branch of symmetric cryptography.It has the advantages of fast encryption and decryption,convenient software and hardware implementation,and easy standardization.It is widely used in resource-constrained devices such as the Internet of Things,cryptographic chips,and smart grids to protect data.Safety.Since the lightweight block cipher RAIN is a new encryption algorithm proposed by Chinese scholars,although it has a good ability to resist side channel attacks,there are not many security analysis results yet.Therefore,analyzing the security of the RAIN algorithm can better control the security of the RAIN algorithm and more accurately determine the applicable scenarios of the RAIN algorithm,thereby better protecting national security.This paper mainly focuses on two security analysis methods of the domestic lightweight block cipher RAIN algorithm,and gives the security evaluation of the algorithm under differential attack and boomerang attack respectively.The main research results of this paper are listed as follows:(1)Security analysis of lightweight block cipher RAIN algorithm under differential attack.The encryption process of the cryptographic algorithm is transformed and modeled as a MILP problem.In the modeling process,using the method of mixed linear integer programming MILP,combined with the transfer law of the difference in the nonlinear part and the linear part,the MILP constraint model of the lightweight block cipher RAIN algorithm is described,and the encryption process is respectively Nonlinear and linear transformations are expressed as a series of linear constraints and inequality constraints.In the construction of the linear part MILP model,the situation of not introducing difference and the constraints of row shift and column confusion part are analyzed,and the linear part model is optimized;in the aspect of nonlinear part MILP model construction,a solution to solve the RAIN difference distribution table is designed.Algorithm and RAIN-64 inequality generation algorithm based on MILP,and the Gurobi solver is used to realize the automatic search of the differential route,and a series of inequality characterization results about the S-box are obtained.(2)Security analysis of lightweight block cipher RAIN algorithm under boomerang attack.According to the principle of boomerang attack analysis,an algorithm is designed to realize the establishment of the RAIN-64 algorithm boomerang connection table,and a 6-round RAIN algorithm boomerang attack distinguisher is constructed,and then combined with the relevant encryption The key recovery technology,based on the 6-round discriminator,extends 1 round forward and 3 rounds backward,and realizes the 10-round boomerang attack on the domestic lightweight block cipher algorithm RAIN.The subsequent iterative update design of the lightweight block cipher provides a reference for security analysis.