行标-SM4 Block Cipher Algorithm-SM4加密算法.pdf

SM4 Block Cipher Algorithm

Content

1 Scope 1

2 Terms and Definitions 1

3 Symbols and Acronyms 1

4 Algorithm Structure 1

5 Key and Key Parameters 2

6 Round Function 2

6.1 Round Function Structure 2

6.2 Permutation 2

7 Algorithm Description 3

7.1 Encryption 3

7.2 Decryption 3

7.3 Key Expansion 3

Annex A (informative) Examples 5

A.1 Example 1 5

A.2 Example 2 6

SM4 Block Cipher Algorithm

1Scope

This document specifies the SM4 block cipher algorithm, including its structure and

description. And this document gives computation examples for SM4 block cipher

algorithm.

This document applies to cipher application using block cipher algorithm.

2Terms and Definitions

The following terms and definitions are applied to this document.

2.1 block length

bit size of one block plaintext

2.2 key length

bit size of the cipher key

2.3 key expansion algorithm

an algorithm that transforms the cipher key into round keys

2.4 rounds

the number of round function iterations

2.5 word

a bit string of length 32 bits

2.6 S-box

a permutation with 8-bit input and 8-bit output, represented as (·)

3Symbols and Acronyms

The following symbols and acronyms are applied to this document.

⊕ logical exclusive-or of 32-bit words

left circular rotation by bits

4Algorithm Struc