Security SBOX realization method and apparatus

Abstract

The invention provides a security SBOX realization method and apparatus. The method comprises: receiving input data of a security SBOX, wherein the input data of the security SBOX comprises data B which is subjected to mask processing and a corresponding mask randomized number R1, and the calculation function of a number, whose ordinal number is I, in the security SBOX is a first function G(i, A, F(A)) which relates to the ordinal number I, an initial SBOX input variable A and an output variable F(A); and according to the security SBOX, the input data of the security SBOX and a second function P(G(i), i, B, R1, R2), calculating the output data of the security SBOX, wherein the second function P(G(i), i, B, R1, R2)=F(A, G(i), i)delta R2, F(A, G(i), i) is inverse transformation of the first function, B=A delta R1, R2 is any one randomized number, and delta is mask operation. By use of the method provided by the invention, reformulation of a table according to different mask randomized numbers is unnecessary, and combination logic circuits for calculation is also simplified.

Description

technical field [0001] The invention relates to symmetric encryption technology, in particular to a method and device for realizing a secure SBOX. Background technique [0002] Symmetric cryptosystems are currently widely used, which makes the design security of symmetric cryptosystems highly valued. The core module in the symmetric cryptosystem is SBOX (substitution box), therefore, the secure SBOX implementation is particularly important. [0003] In addition, in the security cryptographic system, the input data of the secure SBOX is mainly the data that uses random numbers to hide the data, that is, the data processed by the masking technology. For example, the original data is x, and the random data m is added, and the The raw data mask is Thereby ensuring the security of the system. Moreover, in order to defend against high-level side-channel attacks, the random numbers used in each round of encryption and decryption are different. [0004] There are two implementa...

AI Technical Summary

Problems solved by technology

However, when there is no fixed operation relationship between the input and output of the security SBOX (data encryption algorithm (Data Encryption Algorithm, DES)), it is necessary to calculate the value storage of the security SBOX in advance according to different random numbers before each encryption and decryption. In the memory, the lookup table is used to obtain the required value in the process of encryption and decryption. Obviously, this method needs to use an additional clock to recreate the table when the random number is different each time, and store it, which is expensive.

Images