HATS Product Notice

This Product Notice describes the scope, limitations, and verification guarantees of HATS (H33 Attestation and Trust Standard) certification. Organizations adopting HATS, relying parties evaluating HATS attestation data, and independent verifiers should read this notice to understand what HATS certifies, what it does not certify, and the boundaries of its guarantees.

What HATS Certifies

HATS certification attests that an organization's systems produce continuous, cryptographically signed records demonstrating that defined security controls were verified and found operational at specific times. HATS is a publicly available technical conformance standard for continuous AI trustworthiness; certification under HATS provides independently verifiable evidence that a system satisfies the standard's defined controls.

Specifically, HATS certification means that: (1) the organization has deployed HATS-compliant verification nodes that perform the checks required by their declared conformance level; (2) each verification check produces a post-quantum signed attestation record; (3) attestation records are chained in a tamper-evident sequence with hash integrity; (4) the attestation chain is anchored to external ledgers at intervals required by the declared conformance level; and (5) the attestation chain and its verification history are available for independent replay verification.

What HATS Does Not Certify

HATS does not certify that an organization will not experience a security breach. Security controls reduce the probability and severity of breaches but cannot eliminate them. An organization can maintain perfect HATS attestation across all 20 verification checks and still experience a breach through attack vectors outside the scope of those checks, through zero-day vulnerabilities, through social engineering, or through insider threats that circumvent technical controls.

HATS does not certify the effectiveness of security controls against all threats. HATS verifies that controls are present, configured, and operational. It does not simulate attacks against those controls to test their resilience. A firewall rule can be present, configured, and operational while still being insufficient to block a specific attack technique.

HATS does not certify compliance with any external regulatory framework. While HATS checks map to common control requirements in SOC 2, ISO 27001, HIPAA, PCI DSS, and other frameworks, HATS certification is not a substitute for compliance certification under those frameworks. Organizations should consult qualified legal and compliance professionals regarding their regulatory obligations.

HATS does not certify the security of systems, networks, or data outside the scope of the declared verification checks. If an organization declares HATS attestation for a specific set of systems, the attestation does not extend to other systems, even if those systems are on the same network or managed by the same team.

Liability Boundaries

H33.ai, Inc. provides the HATS standard, verification tooling, and attestation infrastructure. H33.ai, Inc. is responsible for the correctness of the cryptographic operations (signature generation, hash computation, chain integrity), the availability of the verification endpoints, and the accuracy of the conformance assessment against the declared conformance level.

H33.ai, Inc. is not responsible for: the security posture of organizations that adopt HATS; the accuracy of verification results produced by nodes operated by the organization or its designees; the interpretation of HATS attestation data by insurers, auditors, regulators, or other relying parties; or any business decisions made in reliance on HATS attestation data.

The attestation chain is a record of what was verified and when. It is not a warranty that the underlying systems are secure, that the controls are sufficient for any particular purpose, or that the organization has met any particular legal or regulatory obligation.

Verification Guarantees

HATS provides the following verification guarantees, subject to the correctness of the underlying cryptographic primitives:

Integrity. Any modification to any attestation record in the chain, including addition, deletion, or alteration of records, is detectable. Each record contains a hash reference to its predecessor. The chain can be verified by recomputing the hash chain and checking each record's signature. Integrity verification requires no trust in any intermediary.

Authenticity. Each attestation record is signed with post-quantum signature schemes. The minimum requirement is ML-DSA-65 (FIPS 204). Verification of the signature proves that the record was produced by a node holding the corresponding private key. The post-quantum signature property ensures that this guarantee persists even after the advent of cryptographically relevant quantum computers.

Non-repudiation. An organization that produces HATS attestation records cannot later deny having produced them, because doing so would require forging the signatures on those records. This guarantee is bounded by the security of the signature schemes and the key management practices of the organization.

Temporal binding. Attestation records include timestamps, and the chain is periodically anchored to external ledgers that provide independent timestamping. This provides evidence that a specific attestation existed at a specific time. The precision of temporal binding depends on the anchoring frequency and the timestamp accuracy of the anchoring ledger.

Replay determinism. A replay query against a valid attestation chain will produce the same result regardless of who performs the replay, when it is performed, or what system is used to perform it. This guarantee enables independent verification by any party.

Independent Verifier Availability

HATS is designed to be verified independently of H33.ai, Inc. The Conformance Suite includes open-source verification tools that any party can use to validate an attestation chain. These tools verify chain integrity, signature validity, temporal binding, and conformance level compliance.

Independent verifiers do not require any relationship with H33.ai, Inc. They do not require API keys, accounts, or licenses. The verification algorithms are fully specified in the HATS Technical Specification, and the cryptographic operations use NIST-standardized algorithms with publicly available implementations.

Organizations that wish to operate independent verification services for commercial purposes (such as insurers offering HATS-based underwriting) may do so without permission from H33.ai, Inc. The HATS standard is a publicly available specification. The attestation format, chain structure, and verification algorithms are documented for this purpose.

Contact

For questions about this Product Notice, contact support@h33.ai. For the full HATS specification, visit the HATS Standard page.