Welcome to the One-Time Pad (OTP) Cipher Tool!

The One-Time Pad is an unbreakable cipher that requires a random key as long as the message. Each character is combined with a key character to produce the ciphertext.

To Encrypt a Message:

1. Enter Plaintext: Type the message you want to encrypt in the "Text" field.
2. Enter Key: Provide a key that is at least as long as the plaintext. You can also generate a random key.
3. Select Mode: Choose "Encrypt".
4. Click Submit: The encrypted message will appear in the output box.

To Decrypt a Message:

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

Security Note: A key should never be reused. For true one-time pad security, the key must be random, used only once, and kept secret.