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16-round SM4-256 white-box password implementation method

A white-box cipher and cipher algorithm technology, which is applied to the encryption algorithm with 128-bit/256-bit plaintext grouping/key grouping, 16-round SM4-256 white-box cipher algorithm scheme and system field, and can solve the 128-bit initial key The length round key generation process has not been improved, the security has not been improved, and the security and reliability are not enough, so as to improve the difficulty of key cracking, increase the length of the key, and take up less space.

Inactive Publication Date: 2019-11-19
BEIJING ELECTRONICS SCI & TECH INST
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Whether it is using group lookup table technology or Intel's high-performance AES instruction set, the speed has been accelerated, but the security has not been improved. The 128-bit initial key length and the generation process of the round key have not been improved, which is not safe and reliable enough.

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  • 16-round SM4-256 white-box password implementation method
  • 16-round SM4-256 white-box password implementation method
  • 16-round SM4-256 white-box password implementation method

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Embodiment Construction

[0022] The scheme proposed by the present invention will be described in further detail below in conjunction with the accompanying drawings, but the scope of the present invention is not limited in any way.

[0023] The scheme proposed by the present invention is improved based on the national standard SM4 encryption algorithm. The improved SM4 cipher algorithm supports 256-bit key length, 128-bit and 256-bit plaintext length, and outputs ciphertext after 16 iterations of initial plaintext and 1 reverse transformation R.

[0024] Take the plaintext length of 256 bits as an example to describe the encryption process in detail.

[0025] Step one, such as figure 2 As shown, in the process of the improved SM4 cryptographic algorithm new mode encryption iterative operation, each round of the round function produces 2 intermediate variables, namely

[0026]

[0027]

[0028] in, is the bit XOR symbol, X i (i=0, 1, ..., 39) are all 32-bit values, which are intermediate va...

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Abstract

The invention discloses an SM4-256 white-box password implementation method, and describes a new mode of an improved SM4 password algorithm when the encryption round number is 16, and the mode supports two conditions that the block length / key length is 128 / 256 and 256 / 256; an improved SM4 white box cryptographic algorithm is provided, an algorithm with a secret key of 256 bits is subjected to white-box processing, each round of the improved SM4 cryptographic algorithm is divided into small blocks, each small block is scrambled and coded, and a coded result is expressed by a lookup table and affine transformation, so that secret key information is hidden in the lookup table. And the algorithm execution efficiency and security are high.

Description

technical field [0001] The invention belongs to the technical field of information security, and in particular relates to a 16-round SM4-256 white-box cipher algorithm scheme and system. The invention also relates to an encryption algorithm with 128-bit / 256-bit plain text grouping / key grouping. Background technique [0002] The SM4 cipher algorithm (formerly known as SMS4) is a block cipher algorithm. The lengths of plaintext blocks, key blocks, and ciphertext blocks are all 128 bits, and the encryption and decryption processes are basically similar. Encryption and decryption are realized through a nonlinear iterative round function of 32 cycles. These include non-linear transformation S-boxes, and linear transformations consisting of cyclic shift XORs. [0003] Patent Document 1 (publication number: CN106712930A, publication date: May 24, 2017) proposes an SM4 encryption method and device, the main principle of which is to decompose the synthetic replacement T calculation...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H04L9/06
CPCH04L9/0618H04L9/0631
Inventor 杨亚涛张也张筱薇赵阳林天祥黄湘颖
Owner BEIJING ELECTRONICS SCI & TECH INST