线性变换和轮密钥异或
发布时间：2025-06-24 17:11:51 作者：北方职教升学中心 阅读量：289
和解密的过程。
SM4算法的Python实现
以下是SM4算法的完整Python代码实现，涵盖了密钥扩展、
SM4算法的加密和解密流程
- 密钥扩展：生成轮密钥，共32个，用于每轮的加密或解密操作。加密、上述Python代码实现了SM4算法的加密和解密过程，可以帮助更深入理解其原理和应用。
总结
SM4算法是一种高效的对称加密算法，在信息安全领域有着广泛应用。S盒替换、
目录
- SM4算法简介
- SM4算法的加密和解密流程
- SM4算法的Python实现
- 代码解释
- 总结
SM4算法是中国国家密码局设计的块密码算法，广泛应用于无线局域网标准和其他安全通信系统中。主要包括密钥扩展、
# S盒，用于字节替换S_BOX =[0xd6,0x90,0xe9,0xfe,0xcc,0xe1,0x3d,0xb7,0x16,0xb6,0x14,0xc2,0x28,0xfb,0x2c,0x05,0x2b,0x67,0x9a,0x76,0x2a,0xbe,0x04,0xc3,0xaa,0x44,0x13,0x26,0x49,0x86,0x06,0x99,0x9c,0x42,0x50,0xf4,0x91,0xef,0x98,0x7a,0x33,0x54,0x0b,0x43,0xed,0xcf,0xac,0x62,0xe4,0xb3,0x1c,0xa9,0xc9,0x08,0xe8,0x95,0x80,0xdf,0x94,0xfa,0x75,0x8f,0x3f,0xa6,0x47,0x07,0xa7,0xfc,0xf3,0x73,0x17,0xba,0x83,0x59,0x3c,0x19,0xe6,0x85,0x4f,0xa8,0x68,0x6b,0x81,0xb2,0x71,0x64,0xda,0x8b,0xf8,0xeb,0x0f,0x4b,0x70,0x56,0x9d,0x35,0x1e,0x24,0x0e,0x5e,0x63,0x58,0xd1,0xa2,0x25,0x22,0x7c,0x3b,0x01,0x21,0x78,0x87,0xd4,0x00,0x46,0x57,0x9f,0xd3,0x27,0x52,0x4c,0x36,0x02,0xe7,0xa0,0xc4,0xc8,0x9e,0xea,0xbf,0x8a,0xd2,0x40,0xc7,0x38,0xb5,0xa3,0xf7,0xf2,0xce,0xf9,0x61,0x15,0xa1,0xe0,0xae,0x5d,0xa4,0x9b,0x34,0x1a,0x55,0xad,0x93,0x32,0x30,0xf5,0x8c,0xb1,0xe3,0x1d,0xf6,0xe2,0x2e,0x82,0x66,0xca,0x60,0xc0,0x29,0x23,0xab,0x0d,0x53,0x4e,0x6f,0xd5,0xdb,0x37,0x45,0xde,0xfd,0x8e,0x2f,0x03,0xff,0x6a,0x72,0x6d,0x6c,0x5b,0x51,0x8d,0x1b,0xaf,0x92,0xbb,0xdd,0xbc,0x7f,0x11,0xd9,0x5c,0x41,0x1f,0x10,0x5a,0xd8,0x0a,0xc1,0x31,0x88,0xa5,0xcd,0x7b,0xbd,0x2d,0x74,0xd0,0x12,0xb8,0xe5,0xb4,0xb0,0x89,0x69,0x97,0x4a,0x0c,0x96,0x77,0x7e,0x65,0xb9,0xf1,0x09,0xc5,0x6e,0xc6,0x84,0x18,0xf0,0x7d,0xec,0x3a,0xdc,0x4d,0x20,0x79,0xee,0x5f,0x3e,0xd7,0xcb,0x39,0x48]# 轮常数，用于密钥扩展FK =[0xa3b1bac6,0x56aa3350,0x677d9197,0xb27022dc]# 固定参数，用于轮密钥生成CK =[0x00070e15,0x1c232a31,0x383f464d,0x545b6269,0x70777e85,0x8c939aa1,0xa8afb6bd,0xc4cbd2d9,0xe0e7eef5,0xfc030a11,0x181f262d,0x343b4249,0x50575e65,0x6c737a81,0x888f969d,0xa4abb2b9,0xc0c7ced5,0xdce3eaf1,0xf8ff060d,0x141b2229,0x30373e45,0x4c535a61,0x686f767d,0x848b9299,0xa0a7aeb5,0xbcc3cad1,0xd8dfe6ed,0xf4fb0209,0x10171e25,0x2c333a41,0x484f565d,0x646b7279]defbyte_sub(byte):"""S盒字节替换"""returnS_BOX[byte]defl_transformation(b):"""线性变换"""returnb ^(b <<2)^(b <<10)^(b <<18)^(b <<24)deft_function(x):"""T函数，包括S盒替换和线性变换"""b =byte_sub((x >>24)&0xFF)<<24|\ byte_sub((x >>16)&0xFF)<<16|\ byte_sub((x >>8)&0xFF)<<8|\ byte_sub(x &0xFF)returnl_transformation(b)defkey_expansion(key):"""密钥扩展生成32轮密钥"""K =[key[i]^FK[i]fori inrange(4)]rk =[]fori inrange(32):temp =K[i]^t_function(K[i +1]^K[i +2]^K[i +3]^CK[i])rk.append(temp)K.append(temp)returnrkdefsm4_encrypt_block(plaintext,key):"""SM4单块加密"""rk =key_expansion(key)X =plaintext.copy()fori inrange(32):temp =X[i]^t_function(X[i +1]^X[i +2]^X[i +3]^rk[i])X.append(temp)returnX[35:31:-1]# 反序输出defsm4_decrypt_block(ciphertext,key):"""SM4单块解密"""rk =key_expansion(key)[::-1]# 轮密钥反序X =ciphertext.copy()fori inrange(32):temp =X[i]^t_function(X[i +1]^X[i +2]^X[i +3]^rk[i])X.append(temp)returnX[35:31:-1]# 反序输出# 示例使用plaintext =[0x01234567,0x89abcdef,0xfedcba98,0x76543210]key =[0x01234567,0x89abcdef,0xfedcba98,0x76543210]ciphertext =sm4_encrypt_block(plaintext,key)print(f"加密后的密文: {ciphertext}")decrypted_text =sm4_decrypt_block(ciphertext,key)print(f"解密后的明文: {decrypted_text}")代码解释
- S_BOX：用于字节替换的非线性变换表。
- 初始轮密钥异或：将输入的数据块与初始密钥异或。
SM4算法简介
SM4是一种对称分组密码算法，每次操作128位数据块，密钥长度也为128位。
