OAuth 2.0 Attestation-Based Client Authentication

5.1. Client Attestation JWT

The Client Attestation MUST be encoded as a "JSON Web Token (JWT)" according to [RFC7519].¶

The following content applies to the JWT Header:¶

• typ: REQUIRED. The JWT type MUST be oauth-client-attestation+jwt.¶

The following content applies to the JWT Claims Set:¶

• iss: REQUIRED. The iss (subject) claim MUST contains a unique identifier for the entity that issued the JWT. In the absence of an application profile specifying otherwise, compliant applications MUST compare issuer values using the Simple String Comparison method defined in Section 6.2.1 of [RFC3986].¶

• sub: REQUIRED. The sub (subject) claim MUST specify client_id value of the OAuth Client.¶

• exp: REQUIRED. The exp (expiration time) claim MUST specify the time at which the Client Attestation is considered expired by its issuer. The authorization server MUST reject any JWT with an expiration time that has passed, subject to allowable clock skew between systems.¶

• cnf: REQUIRED. The cnf (confirmation) claim MUST specify a key conforming to [RFC7800] that is used by the Client Instance to generate the Client Attestation PoP JWT for client authentication with an authorization server. The key MUST be expressed using the "jwk" representation.¶

• iat: OPTIONAL. The iat (issued at) claim MUST specify the time at which the Client Attestation was issued.¶

• nbf: OPTIONAL. The nbf (not before) claim MUST specify the time before which the Client Attestation MUST NOT be accepted for processing.¶

The following additional rules apply:¶

1. The JWT MAY contain other claims. All claims that are not understood by implementations MUST be ignored.¶

2. The JWT MUST be digitally signed using an asymmetric cryptographic algorithm. The authorization server MUST reject the JWT if it is using a Message Authentication Code (MAC) based algorithm. The authorization server MUST reject JWTs with an invalid signature.¶

3. The authorization server MUST reject a JWT that is not valid in all other respects per "JSON Web Token (JWT)" [RFC7519].¶

The following example is the decoded header and payload of a JWT meeting the processing rules as defined above.¶

{
  "typ": "oauth-client-attestation+jwt"
  "alg": "ES256",
  "kid": "11"
}
.
{
  "iss": "https://client.example.com",
  "sub": "https://client.example.com",
  "nbf":1300815780,
  "exp":1300819380,
  "cnf": {
    "jwk": {
      "kty": "EC",
      "use": "sig",
      "crv": "P-256",
      "x": "18wHLeIgW9wVN6VD1Txgpqy2LszYkMf6J8njVAibvhM",
      "y": "-V4dS4UaLMgP_4fY4j8ir7cl1TXlFdAgcx55o7TkcSA"
    }
  }
}

5.2. Client Attestation PoP JWT

The Client Attestation PoP MUST be encoded as a "JSON Web Token (JWT)" according to [RFC7519].¶

The following content applies to the JWT Header:¶

• typ: REQUIRED. The JWT type MUST be oauth-client-attestation-pop+jwt.¶

The following content applies to the JWT Claims Set:¶

• iss: REQUIRED. The iss (subject) claim MUST specify client_id value of the OAuth Client.¶

• exp: REQUIRED. The exp (expiration time) claim MUST specify the time at which the Client Attestation PoP is considered expired. The authorization server MUST reject any JWT with an expiration time that has passed, subject to allowable clock skew between systems. Note that the authorization server may reject JWTs with an "exp" claim value that is unreasonably far in the future.¶

• aud: REQUIRED. The aud (audience) claim MUST specify a value that identifies the authorization server as an intended audience. The [RFC8414] issuer identifier URL of the authorization server MUST be used as a value for an "aud" element to identify the authorization server as the intended audience of the JWT.¶

• jti: REQUIRED. The jti (JWT identifier) claim MUST specify a unique identifier for the Client Attestation PoP. The authorization server MAY ensure that JWTs are not replayed by maintaining the set of used "jti" values for the length of time for which the JWT would be considered valid based on the applicable "exp" instant.¶

• nonce: OPTIONAL. The nonce (nonce) claim MUST specify a String value that is provided by the authorization server to associate the Client Attestation PoP JWT with a particular transaction and prevent replay attacks.¶

• iat: OPTIONAL. The iat (issued at) claim MUST specify the time at which the Client Attestation PoP was issued. Note that the authorization server may reject JWTs with an "iat" claim value that is unreasonably far in the past.¶

• nbf: OPTIONAL. The nbf (not before) claim MUST specify the time before which the Client Attestation PoP MUST NOT be accepted for processing.¶

The following additional rules apply:¶

1. The JWT MAY contain other claims. All claims that are not understood by implementations MUST be ignored.¶

2. The JWT MUST be digitally signed using an asymmetric cryptographic algorithm. The authorization server MUST reject the JWT if it is using a Message Authentication Code (MAC) based algorithm. The authorization server MUST reject JWTs with an invalid signature.¶

3. The public key used to verify the JWT MUST be the key located in the "cnf" claim of the corresponding Client Attestation JWT.¶

4. The Authorization Server MUST reject a JWT that is not valid in all other respects per "JSON Web Token (JWT)" [RFC7519].¶

The following example is the decoded header and payload of a JWT meeting the processing rules as defined above.¶

{
  "typ": "oauth-client-attestation-pop",
  "alg": "ES256"
}
.
{
  "iss": "https://client.example.com",
  "aud": "https://as.example.com",
  "nbf":1300815780,
  "exp":1300819380,
  "jti": "d25d00ab-552b-46fc-ae19-98f440f25064",
  "nonce" : "5c1a9e10-29ff-4c2b-ae73-57c0957c09c4"
}

6.1. Client Attestation HTTP Headers

A Client Attestation JWT and Client Attestation PoP JWT can be included in an HTTP request using the following request header fields.¶

OAuth-Client-Attestation:

A JWT that conforms to the structure and syntax as defined in Section 5.1¶

OAuth-Client-Attestation-PoP:

A JWT that adheres to the structure and syntax as defined in Section 5.2¶

The following is an example of the OAuth-Client-Attestation header.¶

OAuth-Client-Attestation: eyJhbGciOiAiRVMyNTYiLCJraWQiOiAiMTEifQ.eyJ\
pc3MiOiJodHRwczovL2NsaWVudC5leGFtcGxlLmNvbSIsInN1YiI6Imh0dHBzOi8vY2x\
pZW50LmV4YW1wbGUuY29tIiwibmJmIjoxMzAwODE1NzgwLCJleHAiOjEzMDA4MTkzODA\
sImNuZiI6eyJqd2siOnsia3R5IjoiRUMiLCJ1c2UiOiJzaWciLCJjcnYiOiJQLTI1NiI\
sIngiOiIxOHdITGVJZ1c5d1ZONlZEMVR4Z3BxeTJMc3pZa01mNko4bmpWQWlidmhNIiw\
ieSI6Ii1WNGRTNFVhTE1nUF80Zlk0ajhpcjdjbDFUWGxGZEFnY3g1NW83VGtjU0EifX1\
9.SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c

The following is an example of the OAuth-Client-Attestation-PoP header.¶

OAuth-Client-Attestation-PoP: eyJhbGciOiJFUzI1NiJ9.ewogICJpc3MiOiAia\
HR0cHM6Ly9jbGllbnQuZXhhbXBsZS5jb20iLAogICJhdWQiOiAiaHR0cHM6Ly9hcy5le\
GFtcGxlLmNvbSIsCiAgIm5iZiI6MTMwMDgxNTc4MCwKICAiZXhwIjoxMzAwODE5MzgwL\
AogICJqdGkiOiAiZDI1ZDAwYWItNTUyYi00NmZjLWFlMTktOThmNDQwZjI1MDY0IiwKI\
CAibm9uY2UiIDogIjVjMWE5ZTEwLTI5ZmYtNGMyYi1hZTczLTU3YzA5NTdjMDljNCIKf\
Q.coB_mtdXwvi9RxSMzbIey8GVVQLv9qQrBUqmc1qj9Bs

Note that per [RFC9110] header field names are case-insensitive; so OAUTH-CLIENT-ATTESTATION, oauth-client-attestation, etc., are all valid and equivalent header field names. Case is significant in the header field value, however.¶

The OAuth-Client-Attestation and OAuth-Client-Attestation-PoP HTTP header field values uses the token68 syntax defined in Section 11.2 of [RFC9110] (repeated below for ease of reference).¶

OAuth-Client-Attestation       = token68
OAuth-Client-Attestation-PoP   = token68
token68                        = 1*( ALPHA / DIGIT / "-" / "." /
                                     "_" / "~" / "+" / "/" ) *"="

It is RECOMMENDED that the authorization server validate the Client Attestation JWT prior to validating the Client Attestation PoP.¶

6.2. Validating HTTP requests feature client attestations

To validate an HTTP request which contains the client attestation headers, the receiving server MUST ensure the following with regard to a received HTTP request:¶

1. There is precisely one OAuth-Client-Attestation HTTP request header field, where its value is a single well-formed JWT conforming to the syntax outlined in []{client-attestation-jwt}.¶

2. There is precisely one OAuth-Client-Attestation-PoP HTTP request header field, where its value is a single well-formed JWT conforming to the syntax outlined in client-attestation-pop-jwt.¶

3. The signature of the Client Attestation PoP JWT obtained from the OAuth-Client-Attestation-PoP HTTP header verifies with the Client Instance Key contained in the cnf claim of the Client Attestation JWT obtained from the OAuth-Client-Attestation HTTP header.¶

6.3. Client Attestation at the Token Endpoint

While usage of the the client attestation mechanism defined by this draft can be used in a variety of different HTTP requests to different endpoints, usage within the token request as defined by [RFC6749] has particular additional considerations outlined below.¶

The Authorization Server MUST perform all of the checks outlined in Section 6.2 for a received access token request which is making use of the client attestation mechanism as defined by this draft.¶

The following example demonstrates usage of the client attestation mechanism in an access token request (with extra line breaks for display purposes only):¶

POST /token HTTP/1.1
Host: as.example.com
Content-Type: application/x-www-form-urlencoded
OAuth-Client-Attestation: eyJhbGciOiAiRVMyNTYiLCJraWQiOiAiMTEifQ.eyJ\
pc3MiOiJodHRwczovL2NsaWVudC5leGFtcGxlLmNvbSIsInN1YiI6Imh0dHBzOi8vY2x\
pZW50LmV4YW1wbGUuY29tIiwibmJmIjoxMzAwODE1NzgwLCJleHAiOjEzMDA4MTkzODA\
sImNuZiI6eyJqd2siOnsia3R5IjoiRUMiLCJ1c2UiOiJzaWciLCJjcnYiOiJQLTI1NiI\
sIngiOiIxOHdITGVJZ1c5d1ZONlZEMVR4Z3BxeTJMc3pZa01mNko4bmpWQWlidmhNIiw\
ieSI6Ii1WNGRTNFVhTE1nUF80Zlk0ajhpcjdjbDFUWGxGZEFnY3g1NW83VGtjU0EifX1\
9.SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c
OAuth-Client-Attestation-PoP: eyJhbGciOiJFUzI1NiJ9.ewogICJpc3MiOiAia\
HR0cHM6Ly9jbGllbnQuZXhhbXBsZS5jb20iLAogICJhdWQiOiAiaHR0cHM6Ly9hcy5le\
GFtcGxlLmNvbSIsCiAgIm5iZiI6MTMwMDgxNTc4MCwKICAiZXhwIjoxMzAwODE5MzgwL\
AogICJqdGkiOiAiZDI1ZDAwYWItNTUyYi00NmZjLWFlMTktOThmNDQwZjI1MDY0IiwKI\
CAibm9uY2UiIDogIjVjMWE5ZTEwLTI5ZmYtNGMyYi1hZTczLTU3YzA5NTdjMDljNCIKf\
Q.coB_mtdXwvi9RxSMzbIey8GVVQLv9qQrBUqmc1qj9Bs

grant_type=authorization_code&
code=n0esc3NRze7LTCu7iYzS6a5acc3f0ogp4

6.4. Client Attestation at the PAR Endpoint

A Client Attestation can be used at the PAR endpoint instead of alternative client authentication mechanisms like JWT client assertion-based authentication (as defined in Section 2.2 of [RFC7523]).¶

The Authorization Server MUST perform all of the checks outlined in Section 6.2 for a received PAR request which is making use of the client attestation mechanism as defined by this draft.¶

The following example demonstrates usage of the client attestation mechanism in a PAR request (with extra line breaks for display purposes only):¶

POST /as/par HTTP/1.1
Host: as.example.com
Content-Type: application/x-www-form-urlencoded
OAuth-Client-Attestation: eyJhbGciOiAiRVMyNTYiLCJraWQiOiAiMTEifQ.eyJ\
pc3MiOiJodHRwczovL2NsaWVudC5leGFtcGxlLmNvbSIsInN1YiI6Imh0dHBzOi8vY2x\
pZW50LmV4YW1wbGUuY29tIiwibmJmIjoxMzAwODE1NzgwLCJleHAiOjEzMDA4MTkzODA\
sImNuZiI6eyJqd2siOnsia3R5IjoiRUMiLCJ1c2UiOiJzaWciLCJjcnYiOiJQLTI1NiI\
sIngiOiIxOHdITGVJZ1c5d1ZONlZEMVR4Z3BxeTJMc3pZa01mNko4bmpWQWlidmhNIiw\
ieSI6Ii1WNGRTNFVhTE1nUF80Zlk0ajhpcjdjbDFUWGxGZEFnY3g1NW83VGtjU0EifX1\
9.SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c
OAuth-Client-Attestation-PoP: eyJhbGciOiJFUzI1NiJ9.ewogICJpc3MiOiAia\
HR0cHM6Ly9jbGllbnQuZXhhbXBsZS5jb20iLAogICJhdWQiOiAiaHR0cHM6Ly9hcy5le\
GFtcGxlLmNvbSIsCiAgIm5iZiI6MTMwMDgxNTc4MCwKICAiZXhwIjoxMzAwODE5MzgwL\
AogICJqdGkiOiAiZDI1ZDAwYWItNTUyYi00NmZjLWFlMTktOThmNDQwZjI1MDY0IiwKI\
CAibm9uY2UiIDogIjVjMWE5ZTEwLTI5ZmYtNGMyYi1hZTczLTU3YzA5NTdjMDljNCIKf\
Q.coB_mtdXwvi9RxSMzbIey8GVVQLv9qQrBUqmc1qj9Bs

response_type=code&state=af0ifjsldkj&client_id=s6BhdRkqt3
&redirect_uri=https%3A%2F%2Fclient.example.org%2Fcb
&code_challenge=K2-ltc83acc4h0c9w6ESC_rEMTJ3bww-uCHaoeK1t8U
&code_challenge_method=S256&scope=account-information

7.1. Concatenated Serialization Format

This representation is created by concatenating Client Attestation and Client Attestation PoP separated by a tilde ('~') character:¶

<Client Attestation>~<Client Attestation PoP>

This form is similar to an SD-JWT+KB according to Section 5 of [SD-JWT] but does not include Disclosures, uses different typ values and does not include the sd_hash claim in the PoP.¶

This concatenated serialization form allows a the presentation of a Client Attestation and Client Attestation PoP for cases where a header-based approach is unavailable, e.g., to establish trust in a client when using a direct Browser API call.¶

The following is an example of such a concatenated serialization (with extra line breaks for display purposes only):¶

eyJhbGciOiAiRVMyNTYiLCJraWQiOiAiMTEifQ.eyJpc3MiOiJodHRwczovL2NsaWVud\
C5leGFtcGxlLmNvbSIsInN1YiI6Imh0dHBzOi8vY2xpZW50LmV4YW1wbGUuY29tIiwib\
mJmIjoxMzAwODE1NzgwLCJleHAiOjEzMDA4MTkzODAsImNuZiI6eyJqd2siOnsia3R5I\
joiRUMiLCJ1c2UiOiJzaWciLCJjcnYiOiJQLTI1NiIsIngiOiIxOHdITGVJZ1c5d1ZON\
lZEMVR4Z3BxeTJMc3pZa01mNko4bmpWQWlidmhNIiwieSI6Ii1WNGRTNFVhTE1nUF80Z\
lk0ajhpcjdjbDFUWGxGZEFnY3g1NW83VGtjU0EifX19.SflKxwRJSMeKKF2QT4fwpMeJ\
f36POk6yJV_adQssw5c~eyJhbGciOiJFUzI1NiJ9.ewogICJpc3MiOiAiaHR0cHM6Ly9\
jbGllbnQuZXhhbXBsZS5jb20iLAogICJhdWQiOiAiaHR0cHM6Ly9hcy5leGFtcGxlLmN\
vbSIsCiAgIm5iZiI6MTMwMDgxNTc4MCwKICAiZXhwIjoxMzAwODE5MzgwLAogICJqdGk\
iOiAiZDI1ZDAwYWItNTUyYi00NmZjLWFlMTktOThmNDQwZjI1MDY0IiwKICAibm9uY2U\
iIDogIjVjMWE5ZTEwLTI5ZmYtNGMyYi1hZTczLTU3YzA5NTdjMDljNCIKfQ.coB_mtdX\
wvi9RxSMzbIey8GVVQLv9qQrBUqmc1qj9Bs

7.2. Validating the Concatenated Serialization

To validate a client attestation using the concatenated serialization form, the receiving server MUST ensure the following:¶

1. Before the '~' character, there exists precisely a single well-formed JWT conforming to the syntax outlined in client-attestation-jwt.¶

2. After the '~' character, there exists precisely a single well-formed JWT conforming to the syntax outlined in client-attestation-pop-jwt.¶

3. The signature of the Client Attestation PoP JWT obtained after the '~' character verifies with the Client Instance Key contained in the cnf claim of the Client Attestation JWT obtained before the '~' character.¶

8.1. Reuse of a Client Attestation JWT

Implementers should be aware that the design of this authentication mechanism deliberately allows for a Client Instance to re-use a single Client Attestation JWT in multiple interactions/requests with an Authorization Server, whilst producing a fresh Client Attestation PoP JWT. Client deployments should consider this when determining the validity period for issued Client Attestation JWTs as this ultimately controls how long a Client Instance can re-use a single Client Attestation JWT.¶

8.2. Refresh token binding

Authorization servers issuing a refresh token in response to a token request using the client attestation mechanism as defined by this draft MUST bind the refresh token to the Client Instance, and NOT just the client as specified in section 6 [RFC6749]. To prove this binding, the Client Instance MUST use the client attestation mechanism when refreshing an access token. The client MUST also use the same key that was present in the "cnf" claim of the client attestation that was used when the refresh token was issued.¶

9.1. Client Instance Tracking Across Authorization Servers

Implementers should be aware that using the same client attestation across multiple authorization servers could result in correlation of the end user using the Client Instance through claim values (including the Client Instance Key in the cnf claim). Client deployments are therefore RECOMMENDED to use different Client Attestation JWTs with different Client Instance Keys across different authorization servers.¶

10.1. Replay Attack Detection

The following mechanisms exist within this client authentication method in order to allow an authorization server to detect replay attacks for presented client attestation PoPs:¶

• The client uses "jti" (JWT ID) claims for the Client Attestation PoP JWT and the authorization server maintains a list of used (seen) "jti" values for the time of which the JWT would be considered valid based on the applicable "exp" claim. If any Client Attestation PoP JWT would be replayed, the authorization server would recognize the "jti" and respond with an authentication error.¶

• The authorization server provides a nonce for the particular transaction and the client uses it for the "nonce" claim in the Client Attestation PoP JWT. The authorization server validates that the nonce matches for the transaction. This approach may require an additional roundtrip in the protocol. The authorization server MUST ensure that the nonce provides sufficient entropy.¶

• The authorization server may expect the usage of a nonce in the Client Attestation PoP JWT, but instead of providing the nonce explicitly, the client may implicitly reuse an existing artefact, e.g. the authorization code. The authorization server MUST ensure that the nonce provides sufficient entropy.¶

The approach using a nonce explicitly provided by the authorization server gives stronger replay attack detection guarantees, however support by the authorization server is OPTIONAL to simplify mandatory implementation requirements. The "jti" method is mandatory and hence acts as a default fallback.¶

11.1. Registration of attest_jwt_client_auth Token Endpoint Authentication Method

This section registers the value "attest_jwt_client_auth" in the IANA "OAuth Token Endpoint Authentication Methods" registry established by OAuth 2.0 Dynamic Client Registration Protocol [RFC7591].¶

• Token Endpoint Authentication Method Name: "attest_jwt_client_auth"¶

• Change Controller: IESG¶

• Specification Document(s): TBC¶

11.2. HTTP Field Name Registration

This section requests registration of the following scheme in the "Hypertext Transfer Protocol (HTTP) Field Name Registry" [IANA.HTTP.Fields] described in [RFC9110]:¶

• Field Name: OAuth-Client-Attestation¶

• Status: permanent¶

• Reference: Section 6.1 of this specification¶

• Field Name: OAuth-Client-Attestation-PoP¶

• Status: permanent¶

• Reference: Section 6.1 of this specification¶

12.1. Normative References

[IANA.HTTP.Fields]

IANA, "Hypertext Transfer Protocol (HTTP) Field Name Registry", n.d., <https://www.iana.org/assignments/http-fields/http-fields.xhtml>.

[RFC2119]

Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, <https://www.rfc-editor.org/rfc/rfc2119>.

[RFC3986]

Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform Resource Identifier (URI): Generic Syntax", STD 66, RFC 3986, DOI 10.17487/RFC3986, January 2005, <https://www.rfc-editor.org/rfc/rfc3986>.

[RFC7519]

Jones, M., Bradley, J., and N. Sakimura, "JSON Web Token (JWT)", RFC 7519, DOI 10.17487/RFC7519, May 2015, <https://www.rfc-editor.org/rfc/rfc7519>.

[RFC7591]

Richer, J., Ed., Jones, M., Bradley, J., Machulak, M., and P. Hunt, "OAuth 2.0 Dynamic Client Registration Protocol", RFC 7591, DOI 10.17487/RFC7591, July 2015, <https://www.rfc-editor.org/rfc/rfc7591>.

[RFC7800]

Jones, M., Bradley, J., and H. Tschofenig, "Proof-of-Possession Key Semantics for JSON Web Tokens (JWTs)", RFC 7800, DOI 10.17487/RFC7800, April 2016, <https://www.rfc-editor.org/rfc/rfc7800>.

[RFC8174]

Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, <https://www.rfc-editor.org/rfc/rfc8174>.

[RFC8414]

Jones, M., Sakimura, N., and J. Bradley, "OAuth 2.0 Authorization Server Metadata", RFC 8414, DOI 10.17487/RFC8414, June 2018, <https://www.rfc-editor.org/rfc/rfc8414>.

[RFC8725]

Sheffer, Y., Hardt, D., and M. Jones, "JSON Web Token Best Current Practices", BCP 225, RFC 8725, DOI 10.17487/RFC8725, February 2020, <https://www.rfc-editor.org/rfc/rfc8725>.

[RFC9110]

Fielding, R., Ed., Nottingham, M., Ed., and J. Reschke, Ed., "HTTP Semantics", STD 97, RFC 9110, DOI 10.17487/RFC9110, June 2022, <https://www.rfc-editor.org/rfc/rfc9110>.

[RFC9112]

Fielding, R., Ed., Nottingham, M., Ed., and J. Reschke, Ed., "HTTP/1.1", STD 99, RFC 9112, DOI 10.17487/RFC9112, June 2022, <https://www.rfc-editor.org/rfc/rfc9112>.

12.2. Informative References

[ARF]

"The European Digital Identity Wallet Architecture and Reference Framework", n.d..

[RFC6749]

Hardt, D., Ed., "The OAuth 2.0 Authorization Framework", RFC 6749, DOI 10.17487/RFC6749, October 2012, <https://www.rfc-editor.org/rfc/rfc6749>.

[RFC7523]

Jones, M., Campbell, B., and C. Mortimore, "JSON Web Token (JWT) Profile for OAuth 2.0 Client Authentication and Authorization Grants", RFC 7523, DOI 10.17487/RFC7523, May 2015, <https://www.rfc-editor.org/rfc/rfc7523>.

[RFC9334]

Birkholz, H., Thaler, D., Richardson, M., Smith, N., and W. Pan, "Remote ATtestation procedureS (RATS) Architecture", RFC 9334, DOI 10.17487/RFC9334, January 2023, <https://www.rfc-editor.org/rfc/rfc9334>.

[SD-JWT]

Fett, D., Yasuda, K., and B. Campbell, "Selective Disclosure for JWTs (SD-JWT)", Work in Progress, Internet-Draft, draft-ietf-oauth-selective-disclosure-jwt-13, 18 October 2024, <https://datatracker.ietf.org/doc/html/draft-ietf-oauth-selective-disclosure-jwt-13>.