Welcome to the Playfair Cipher Tool!

The Playfair cipher is a digraphic substitution cipher that encrypts pairs of letters (digraphs) instead of single letters.

To Encrypt a Message:

1. Select Operation: Choose "Encrypt".
2. Enter a Key: Provide a keyword. The key square will be generated based on this. You can also generate a random key.
3. Enter Plaintext: Type the message you want to encrypt.
4. Click Submit: The encryption steps and the final ciphertext will be displayed.

To Decrypt a Message:

1. Select Operation: Choose "Decrypt".
2. Use the Original Key: Enter the same key that was used for encryption.
3. Enter Ciphertext: Paste the encrypted text into the "Text" field.
4. Click Submit: The decryption steps and the original message will be revealed.

Note: The Playfair cipher uses a 5x5 grid of letters. 'J' is typically treated as 'I'.