Implementation method and device of security sbox

Abstract

The present invention provides a security SBOX implementation method and device, the method includes: receiving the input data of the security SBOX, the input data of the security SBOX includes the masked data B and the corresponding masked random number R1, wherein, the calculation function of the number whose ordinal number is i in the security SBOX is the first function G(i, A, F) about the ordinal number i, the input variable A and the output variable F(A) of the initial SBOX (A)); Calculate the output data of the security SBOX according to the input data of the security SBOX, the security SBOX and the second function P(G(i), i, B, R1, R2), wherein, The second function P(G(i), i, B, R1, R2)=F(A, G(i), i)△R2, F(A, G(i), i) is the first The inverse transformation of a function, B=A△R1, R2 is any random number, and △ is a mask operation. The method not only does not need to recreate the table according to different mask random numbers, but also simplifies the combinational logic circuit used for calculation.

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, DES), the value storage of the security SBOX needs to be calculated 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.

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