XChaCha20-Poly1305 encrypt
Encrypt a file with XChaCha20-Poly1305 under a password, on your device.
XChaCha20-Poly1305 encrypt stretches your password with PBKDF2-HMAC-SHA256 at 210,000 iterations, then encrypts under a 24-byte nonce, twice the length ChaCha20-Poly1305 encrypt uses. A fresh 16-byte salt and that nonce are drawn each run and stored ahead of the ciphertext, and the file is named by adding .xchacha20p1305. A forgotten password cannot be recovered, since the tool keeps no copy of it.
Questions
How is this different from ChaCha20-Poly1305 encrypt?
Only the nonce length: 24 bytes here instead of 12, which is what lets the nonce be chosen randomly with a much lower collision risk. The password derivation is identical.
How is the key derived?
PBKDF2-HMAC-SHA256 at 210,000 iterations over your password, with a fresh 16-byte salt drawn each run.
How is the output named?
The original name with .xchacha20p1305 added.
Can I recover a lost password?
No, the tool keeps no copy of it once encryption finishes.
Can I use this from the command line?
Yes, the same code runs on the page, the CLI and MCP.