Recover plaintext from AES ciphertext when you supply the matching passphrase and mode
Protect messages with AES symmetric encryption—the modern standard for confidential data
Decode legacy DES ciphertext for compatibility testing—56-bit DES is not secure today
Encrypt with single DES for education and legacy interoperability, not production secrets
Decrypt Triple-DES (3DES) ciphertext when the same passphrase and settings were used to encrypt
Apply Triple-DES encryption by running DES three times for stronger legacy block protection
Decrypt Rabbit stream-cipher output when you know the original secret key bytes
Encrypt with the Rabbit stream cipher—a fast eSTREAM portfolio algorithm for short payloads
Decode RC4 ciphertext for legacy compatibility checks and capture-the-flag puzzles
Encrypt with RC4 stream cipher—deprecated in TLS but still found in older applications
Decrypt RC4-drop ciphertext that skips the first 256 keystream bytes before encoding
Encrypt using RC4-drop, discarding initial keystream bytes to reduce bias attacks