| crypto/hmac | Package hmac implements the Keyed-Hash Message Authentication Code (HMAC) as defined in U.S. Federal Information Processing Standards Publication 198. |
| crypto/sha256 | Package sha256 implements the SHA224 and SHA256 hash algorithms as defined in FIPS 180-4. |
| go.mau.fi/libsignal/kdf | Package kdf provides a key derivation function to calculate key output and negotiate shared secrets for curve X25519 keys. |
| go.mau.fi/libsignal/keys/message | Package message provides a structure for message keys, which are symmetric keys used for the encryption/decryption of Signal messages. |