Cryptographic attestations

What are attestations?

An attestation is a cryptographically signed proof that a verification occurred. It:

Uses ES256 (ECDSA P-256) signatures
Is formatted as a JWT
Can be verified independently
Can be stored on-chain

Requesting attestations

result = client.verify(
    "2+2=4",
    include_attestation=True
)

print(result.attestation)
# eyJhbGciOiJFUzI1NiIsInR5cCI6InF3ZWQtYXR0ZXN...

Fail-closed contract

Since PR #194 (Issue #188): create_verification_attestation() never returns None. It always returns an AttestationResult with status set to ISSUED, BLOCKED, or UNVERIFIABLE. You MUST check result.is_issued before you treat the attestation as valid. A missing or failed attestation must hard-block the verification path. Never downgrade it to VERIFIED.

`AttestationResult`

status

AttestationStatus

required

Lifecycle state of the attestation. One of ISSUED, BLOCKED, or UNVERIFIABLE.

token

string | None

Signed JWT string. Present only when status == ISSUED; None otherwise.

error_code

string | None

Machine-readable failure code: "SIGNING_FAILURE" when signing failed, "CRYPTO_UNAVAILABLE" when the cryptography / PyJWT package is not installed, None on success.

error

string | None

Human-readable failure detail. None on success.

is_issued

bool

Property. True only when status is AttestationStatus.ISSUED. You must check this flag before you use token.

`AttestationStatus` values

Status	Meaning	`token`	`error_code`
`ISSUED`	QWED signed the attestation.	JWT string	`None`
`BLOCKED`	Crypto is available but signing failed (key error, JWT error). Hard block.	`None`	`SIGNING_FAILURE`
`UNVERIFIABLE`	`cryptography` / `PyJWT` not installed. QWED did not attempt signing.	`None`	`CRYPTO_UNAVAILABLE`
`VALID` / `EXPIRED` / `REVOKED`	Lifecycle states for previously issued attestations during verification.	—	—

Caller pattern

from src.qwed_new.core.attestation import create_verification_attestation

result = create_verification_attestation(
    status="VERIFIED",
    verified=True,
    engine="math",
    query="2+2=4",
)

if not result.is_issued:
    # Fail-closed: do not proceed as VERIFIED without a proof artifact
    raise RuntimeError(f"Attestation unavailable [{result.error_code}]: {result.error}")

use(result.token)

Key lifecycle auditability

Every IssuerKeyPair records generated_at (epoch seconds) and key_continuity_policy. QWED emits a structured log entry (attestation.key_generated) on every new key generation, so you can audit continuity events.

key_continuity_policy

string

default:"ephemeral"

Policy for the issuer key pair. Must be one of "ephemeral" (in-memory, non-persistent — default) or "persistent" (durably stored, e.g. external KMS). Any other value raises ValueError.

AttestationService.get_issuer_info() now includes key_generated_at and key_continuity_policy alongside the existing issuer registry fields.

Attestation structure

{
  "alg": "ES256",
  "typ": "qwed-attestation+jwt",
  "kid": "did:qwed:node:production#signing-key-2024"
}

Payload

{
  "iss": "did:qwed:node:production",
  "sub": "sha256:abc123...",
  "iat": 1703073600,
  "exp": 1734609600,
  "jti": "att_xyz789",
  "qwed": {
    "version": "1.0",
    "result": {
      "status": "VERIFIED",
      "verified": true,
      "engine": "math",
      "confidence": 1.0
    },
    "query_hash": "sha256:def456...",
    "proof_hash": "sha256:ghi789..."
  }
}

Verifying attestations

Using the API

valid, claims, error = client.verify_attestation(jwt)
if valid:
    print(f"Verified by: {claims['iss']}")

Using the SDK

from qwed_sdk import verify_attestation

is_valid = verify_attestation(
    jwt="eyJhbGci...",
    trusted_issuers=["did:qwed:node:production"]
)

Trust anchors

QWED maintains a registry of trusted attestation issuers:

Issuer DID	Name	Status
`did:qwed:node:production`	QWED Production	✅ Active
`did:qwed:node:staging`	QWED Staging	✅ Active

Attestation chains

Link multiple attestations together:

attestation1 = client.verify("step1", include_attestation=True)
attestation2 = client.verify(
    "step2",
    include_attestation=True,
    chain_id="chain_abc",
    chain_index=1,
    previous_attestation=attestation1.jti
)

Use cases

Audit Trails - Prove AI outputs were verified
Compliance - Regulatory verification records
Blockchain - Anchor proofs on-chain
Badges - Show verification status in UIs

Badge integration

Embed attestation badges:

![Verified](https://api.qwedai.com/badge/attestation/att_xyz789)

Production path

Deployment

CI/CD

Security & Compliance

What are attestations?

Requesting attestations

Fail-closed contract

`AttestationResult`

`AttestationStatus` values

Caller pattern

Key lifecycle auditability

Attestation structure

Header

Payload

Verifying attestations

Using the API

Using the SDK

Trust anchors

Attestation chains

Use cases

Badge integration

​What are attestations?

​Requesting attestations

​Fail-closed contract

​AttestationResult

​AttestationStatus values

​Caller pattern

​Key lifecycle auditability

​Attestation structure

​Header

​Payload

​Verifying attestations

​Using the API

​Using the SDK

​Trust anchors

​Attestation chains

​Use cases

​Badge integration

What are attestations?

Requesting attestations

Fail-closed contract

`AttestationResult`

`AttestationStatus` values

Caller pattern

Key lifecycle auditability

Attestation structure

Header

Payload

Verifying attestations

Using the API

Using the SDK

Trust anchors

Attestation chains

Use cases

Badge integration