ChaCha20 / XChaCha20-Poly1305
Modern stream cipher (AEAD)
100% local — nothing is uploaded
Parameters
Key (32 bytes)
Nonce (12 bytes)
AAD (optional)
Output
Output
—
How to use
- Pick a variant: ChaCha20 (raw stream) or a Poly1305 AEAD.
- Provide a 32-byte key (passphrase or raw hex) and a nonce.
- Encrypt or decrypt; AEAD modes verify integrity automatically.
FAQ
ChaCha20 or AES?
Both are secure. ChaCha20 is faster without hardware AES support and is the basis of TLS 1.3 suites like TLS_CHACHA20_POLY1305_SHA256.
What is XChaCha20?
The 24-byte-nonce variant: safe to generate nonces randomly, which removes the counter-management pitfalls of the 12-byte original.