SecureRandom

CSPRNG via Go crypto/rand — not math RNG. Use for nonces, salts, tokens, and key material.

// ( n:i -- bytes:ByteList )
32 SecureRandom.bytes^
16 SecureRandom.bytes^   // e.g. Argon2id salt

Cipher.generateNonce^ draws a nonce of the correct length for that AEAD via the same source.