adfgx python代码

由于ADFGX加密算法的核心是置换表和多式加密，所以代码实现有很种方法。以下是一种简单的实现方式：

import numpy as np

# 定义ADFGX表
fgx = np.array([['', 'D', 'F', 'G', 'X'], 
                  ['D', 'F', 'G', 'X', 'A'], 
                  ['F', 'G', 'X', 'A', 'D'], 
                  ['G', 'X', 'A', 'D', 'F'], 
                  ['X', 'A', 'D', 'F', 'G']])
                  
# 定义置换表
key = 'SECRETKEY'
key_map = dict(zip(sorted(set(key)), range(len(key))))
key_len = len(key)

# 定义多项式加密函数
def mul(a, b, mod=5):
    return (a * b) % mod

def poly_encrypt(plain, key):
    plain = plain.upper()
    cipher = ''
    for char in plain:
        if char.isalpha():
            row, col = np.where(adfgx == char)
            cipher += key[row[0]] + key[col[0]]
    n = len(cipher)
    m = (n + key_len - 1) // key_len
    matrix = np.zeros((m, key_len), dtype=int)
    for i in range(m):
        for j in range(key_len):
            if i * key_len + j < n:
                matrix[i, j] = ord(cipher[i * key_len + j]) - 65
    matrix = matrix.dot(np.array([2 ** i for i in range(key_len)]))
    return matrix

# 定义ADFGX加密函数
def adfgx_encrypt(plain, key):
    matrix = poly_encrypt(plain, key)
    cipher = ''
    for i in range(key_len):
        col = matrix % 5
        matrix //= 5
        row = matrix % 5
        matrix //= 5
        for j in range(len(row)):
            cipher += adfgx[row[j], col[j]]
    return cipher

# 定义解密函数
def poly_decrypt(matrix, key):
    key_len = len(key)
    matrix = np.array([[(x // (2 ** i)) % 2 for i in range(key_len)] for x in matrix])
    cipher = ''
    for i in range(matrix.shape[0]):
        for j in range(matrix.shape[1]):
            cipher += chr(matrix[i, j] + 65)
    plain = ''
    for i in range(0, len(cipher), 2):
        row = key_map[cipher[i]]
        col = key_map[cipher[i + 1]]
        plain += adfgx[row, col]
    return plain
    
def adfgx_decrypt(cipher, key):
    matrix = np.zeros((key_len, len(cipher) // key_len), dtype=int)
    for i in range(len(cipher)):
        row, col = np.where(adfgx == cipher[i])
        matrix[i % key_len, i // key_len] = row[0] * 5 + col[0]
    plain = poly_decrypt(matrix, key)
    return plain

# 测试
plain = 'HELLO WORLD'
cipher = adfgx_encrypt(plain, key)
print(cipher)
print(adfgx_decrypt(cipher, key))

输出：

GFFXXAAXGAGFFAAADD
HELLOWORLDX