aztec-crypto

Higher-level cryptographic primitives built on top of aztec-core: key derivation, Pedersen, Schnorr, address derivation, and SHA-512 → Grumpkin scalar reduction.

Source: crates/crypto/src/.

Module Map

The crate also re-exports aztec_core::hash::{compute_address, compute_secret_hash} for ergonomics.

Key Derivation

The Aztec key hierarchy splits a master secret into four master keys plus an application-scoped signing key:

use aztec_crypto::{derive_keys, DerivedKeys, KeyType};

let DerivedKeys {
    master_nullifier_hiding_key,
    master_incoming_viewing_secret_key,
    master_outgoing_viewing_secret_key,
    master_tagging_secret_key,
    public_keys,                 // PublicKeys bundle
} = derive_keys(&secret_key);

Individual derivation functions are exposed for fine-grained use:

• derive_master_nullifier_hiding_key
• derive_master_incoming_viewing_secret_key
• derive_master_outgoing_viewing_secret_key
• derive_master_tagging_secret_key
• derive_signing_key (Grumpkin scalar used by Schnorr accounts)
• derive_public_key_from_secret_key (Grumpkin scalar mult against generator)

Application-scoped derivations:

• compute_app_secret_key(master, app_address, key_type)
• compute_app_nullifier_hiding_key(master, app_address)
• compute_ovsk_app(master, app_address)

KeyType distinguishes the four master keys when computing app-scoped derivations.

Schnorr Signatures

use aztec_crypto::{schnorr_sign, schnorr_verify, SchnorrSignature};

let sig: SchnorrSignature = schnorr_sign(&message, &signing_key);
assert!(schnorr_verify(&message, &public_key, &sig));

The sign/verify pair matches barretenberg’s Grumpkin Schnorr scheme used by default Aztec accounts.

Pedersen Hash

pedersen_hash(inputs, generator_index) — Pedersen commitment matching the TS SDK’s pedersenHash. Used for compatibility with historical protocol components that predate Poseidon2.

Address Derivation

use aztec_crypto::complete_address_from_secret_key_and_partial_address;
let complete = complete_address_from_secret_key_and_partial_address(&sk, &partial);

Produces a CompleteAddress (address + public keys + partial address).

Full API

Bundled rustdoc: api/aztec_crypto/. Local regeneration:

cargo doc -p aztec-crypto --open

See Also

• aztec-core — underlying field / point types and Poseidon2.
• aztec-account — consumers of derive_keys + schnorr_sign.