栅栏密码python详细例子

栅栏密码（Fence Pattern），也称为矩阵模式或阶梯密码，是一种加密技术，通过将明文字符按照一定规则分布在矩阵中，形成类似栅栏的样子。这里给你提供一个简单的Python实现，我们将使用二维列表来表示这个栅栏。

def fence_cipher(text, rows):
    encrypted_text = [[' ' for _ in range(len(text))] for _ in range(rows)]
    direction = True

    row, col = 0, 0
    for char in text:
        encrypted_text[row][col] = char
        if (direction and row == rows - 1) or (not direction and col == 0):
            direction = not direction
        elif direction:
            row += 1
        else:
            col -= 1

    return ''.join(''.join(row) for row in encrypted_text)

# 示例
plaintext = "Hello, World!"
rows = 3
encrypted = fence_cipher(plaintext, rows)
print("原文:", plaintext)
print("加密后:", encrypted)

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