9x9 Playfair Cipher with XOR and Left Shift

Instructions:

1. Enter your Playfair key (or leave blank for default key)

2. Enter XOR key (used after encryption/before decryption)

3. Enter text to encrypt or decrypt

4. Click "Encrypt" or "Decrypt" button

Note: Encryption process: Playfair → XOR → Left Shift 1 bit

Decryption process: Right Shift 1 bit → XOR → Playfair