Guides

Each guide explains how to accomplish a common task, with the recommended algorithm and complete code that you can copy. The alternatives, and when to prefer them, come at the end.

I want to…	Recommended	Guide
Encrypt data with a secret key	AES-GCM	Encrypt data with a secret key
Encrypt data with a password	scrypt + AES-GCM	Work with passwords
Store and check users’ passwords	bcrypt	Work with passwords
Encrypt data for a recipient’s public key	HPKE	Encrypt data for a recipient’s public key
Sign data, or verify a signature	Ed25519	Sign data and verify signatures
Compute a hash of data or of a file	SHA-256	Hash data and authenticate messages
Authenticate a message with a secret key (MAC)	HMAC-SHA256	Hash data and authenticate messages
Generate, save, and load keys	PEM files (PKCS#8)	Generate, save, and load keys
Agree on a secret key with another party	ECDH (P-256) + HKDF	Generate, save, and load keys