Hill Cipher Encryption

import numpy as np

def generate_key(n):
    # Generate a random n x n matrix as the key
    return np.random.randint(0, 26, size=(n, n))

def matrix_to_string(matrix):
    return ''.join(''.join(chr((x % 26) + ord('A')) for x in row) for row in matrix)

def string_to_matrix(text, n):
    return [[ord(char) - ord('A') for char in text[i:i+n]] for i in range(0, len(text), n)]

def encrypt_hill(message, key):
    n = len(key)
    
    # Pad the message if its length is not a multiple of n
    message += 'X' * (n - len(message) % n) if len(message) % n != 0 else ''
    
    message_matrix = string_to_matrix(message, n)
    key_matrix = np.array(key)
    
    encrypted_matrix = np.dot(message_matrix, key_matrix) % 26
    encrypted_text = matrix_to_string(encrypted_matrix)

    return encrypted_text

if __name__ == "__main__":
    # Get plaintext input from the user
    plaintext = input("Enter the plaintext message: ").upper()

    # Generate a random key matrix
    key_size = int(input("Enter the size of the key matrix (e.g., 2 for 2x2, 3 for 3x3): "))
    key = generate_key(key_size)

    # Encrypt the message using Hill cipher
    ciphertext = encrypt_hill(plaintext, key)

    # Display the results
    print("\nGenerated Key Matrix:")
    print(key)

    print("\nOriginal Message:", plaintext)
    print("Encrypted Message:", ciphertext)