Key Attestation schema (key-attestation+jwt)

The Key Attestation (KA) is a JWT with media type key-attestation+jwt (registered in OpenID4VCI v1.0 IANA Appendix G.6.2). Its claims are defined in Appendix D, Key Attestations. The KA attests one or more keys held in the same key storage component (the WSCD), so the Issuer can trust the keys a credential will be bound to.

JOSE header

Field	Status	Notes
typ	REQUIRED	MUST be key-attestation+jwt.
alg	REQUIRED	Asymmetric signature algorithm (e.g. ES256).
x5c / kid	(one of)	Key identification for the attestation issuer (the Wallet Provider).

Payload claims

Claim	Status	Meaning
iss	OPTIONAL	Issuer of the Key Attestation, when present.
iat	REQUIRED	Time the KA was issued.
exp	OPTIONAL	Expiry; required when the KA is not bound to a proof's freshness.
attested_keys	REQUIRED	Non-empty array of attested public keys (JWK, RFC 7517) from the same key storage component.
key_storage	OPTIONAL	Array of strings asserting the attack-potential resistance of the key storage component (values in Appendix D.2).
user_authentication	OPTIONAL	Array of strings asserting the resistance of the user-authentication methods guarding the keys.
key_storage_status	OPTIONAL	Status information (e.g. token status list) for the attested keys.
nonce	OPTIONAL	Server-provided nonce, when the KA is requested fresh.

OpenID4VCI vs TS3

OpenID4VCI v1.0 and the EUDI TS3 v1.5 profile differ in the KA. Switch tabs to compare the decoded token the playground signs for each.

OpenID4VCI v1.0

Header (key-attestation+jwt):

{
  "typ": "key-attestation+jwt",
  "alg": "ES256",
  "x5c": ["MIIB4DCC... (Wallet Provider certificate)"]
}

Payload:

{
  "iss": "https://wallet-provider.igrant.io",
  "iat": 1780737559,
  "exp": 1788513559,
  "key_storage": ["iso_18045_moderate"],
  "user_authentication": ["iso_18045_moderate"],
  "attested_keys": [
    {"kid": "k0", "kty": "EC", "crv": "P-256", "x": "...", "y": "..."},
    {"kid": "k1", "kty": "EC", "crv": "P-256", "x": "...", "y": "..."}
  ]
}

TS3 v1.5

Header (keyattestation+jwt, no hyphen):

{
  "typ": "keyattestation+jwt",
  "alg": "ES256",
  "x5c": ["MIIB4DCC... (Wallet Provider certificate)"]
}

Payload (no iss; identity is taken from x5c):

{
  "iat": 1780737559,
  "exp": 1788513559,
  "certification": "https://wallet-provider.igrant.io/certification/wscd/GlobalPlatform/",
  "key_storage_status": {
    "status": {"status_list": {"idx": 7, "uri": "https://wallet-provider.igrant.io/wua-type-statuslists/3"}},
    "exp": 1791105559
  },
  "attested_keys": [
    {"kty": "EC", "crv": "P-256", "x": "...", "y": "..."},
    {"kty": "EC", "crv": "P-256", "x": "...", "y": "..."}
  ],
  "key_storage": ["iso_18045_high"],
  "user_authentication": ["iso_18045_high", "iso_18045_moderate"]
}

Show TS3 v1.5 changes