jose J. Miller Internet-Draft Ping Identity Intended status: Standards Track M. Jones Expires: 23 April 2025 Self-Issued Consulting D. Waite Ping Identity 20 October 2024 JSON Proof Algorithms draft-ietf-jose-json-proof-algorithms-latest Abstract The JSON Proof Algorithms (JPA) specification registers cryptographic algorithms and identifiers to be used with the JSON Web Proof, JSON Web Key (JWK), and COSE specifications. It defines IANA registries for these identifiers. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at https://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." This Internet-Draft will expire on 23 April 2025. Copyright Notice Copyright (c) 2024 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/ license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License. Table of Contents 1. Introduction 2. Conventions and Definitions 3. Terminology 4. Background 5. Algorithm Basics 5.1. Issue 5.2. Confirm 5.3. Present 5.4. Verify 6. Algorithm Specifications 6.1. Single Use 6.1.1. JWS Algorithm 6.1.2. Holder Setup 6.1.3. Issuer Setup 6.1.4. Signing payloads 6.1.5. Issuer Protected Header 6.1.6. Payloads 6.1.7. Proof 6.1.8. Presentation Protected Header 6.1.9. Presentation 6.1.10. Verification 6.1.11. JPA Registration 6.2. BBS 6.2.1. JPA Algorithms 6.2.2. Key Format 6.2.3. Issuance 6.2.4. Issuance Proof Verification 6.2.5. Presentation 6.2.6. Presentation Verification 6.3. Message Authentication Code 6.3.1. Holder Setup 6.3.2. Issuer Setup 6.3.3. Combined MAC Representation 6.3.4. Issuer Proof 6.3.5. Presentation Protected Header 6.3.6. Presentation Proof 6.3.7. Verification of the Presentation Proof 6.3.8. JPA Registration 7. Security Considerations 8. IANA Considerations 8.1. JSON Web Proof Algorithms Registry 8.1.1. Registration Template 8.1.2. Initial Registry Contents 8.1.2.1. Single-Use JWP using ES256 Algorithm 8.1.2.2. Single-Use JWP using ES384 Algorithm 8.1.2.3. Single-Use JWP using ES512 Algorithm 8.1.2.4. BBS using SHA-256 Algorithm 8.1.2.5. BBS Proof using SHA-256 Algorithm 8.1.2.6. MAC-H256 Algorithm 8.1.2.7. MAC-H384 Algorithm 8.1.2.8. MAC-H512 Algorithm 8.1.2.9. MAC-K25519 Algorithm 8.1.2.10. MAC-K448 Algorithm 8.1.2.11. MAC-H256K Algorithm 9. References 9.1. Normative References 9.2. Informative References Appendix A. Example JWPs A.1. Example Single-Use JWP A.2. Example BBS JWP A.3. Example MAC JWP Appendix B. Acknowledgements Appendix C. Document History Authors' Addresses 1. Introduction The JSON Web Proof (JWP) [I-D.ietf-jose-json-web-proof] draft establishes a new secure container format that supports selective disclosure and unlinkability using Zero-Knowledge Proofs (ZKPs) or other cryptographic algorithms. | Editor's Note: This draft is still early and incomplete. There | will be significant changes to the algorithms as currently defined | here. Please do not use any of these definitions or examples for | anything except personal experimentation and learning. | Contributions and feedback are welcomed at https://github.com/ | ietf-wg-jose/json-web-proof (https://github.com/ietf-wg-jose/json- | web-proof). 2. Conventions and Definitions The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here. The roles of "issuer", "holder", and "verifier" are used as defined by the VC Data Model [VC-DATA-MODEL-2.0]. The term "presentation" is also used as defined by this source, but the term "credential" is avoided in this specification to minimize confusion with other definitions. 3. Terminology The terms "JSON Web Signature (JWS)", "Base64url Encoding", "Header Parameter", "JOSE Header", "JWS Payload", "JWS Signature", and "JWS Protected Header" are defined by [RFC7515]. The terms "JSON Web Proof (JWP)", "JWP Payload", "JWP Proof", and "JWP Protected Header" are defined by [I-D.ietf-jose-json-web-proof]. These terms are defined by this specification: Stable Key: An asymmetric key-pair used by an issuer that is also shared via an out-of-band mechanism to a verifier to validate the signature. Ephemeral Key: An asymmetric key-pair that is generated for one-time use by an issuer and never stored or used again outside of the creation of a single JWP. Presentation Key: An asymmetric key-pair that is generated by a holder and used to ensure that a presentation is not able to be replayed by any other party. 4. Background JWP defines a container binding together a protected header, one or more payloads, and a cryptographic proof. It does not define any details about the interactions between an application and the cryptographic libraries that implement proof-supporting algorithms. Due to the nature of ZKPs, this specification also documents the subtle but important differences in proof algorithms versus those defined by the JSON Web Algorithms [RFC7518]. These differences help support more advanced capabilities such as blinded signatures and predicate proofs. 5. Algorithm Basics The four principal interactions that every proof algorithm MUST support are [issue](#issue), [confirm](#confirm), [present](#present), and [verify](#verify). 5.1. Issue The JWP is first created as the output of a JPA's issue operation. Every algorithm MUST support a JSON issuer protected header along with one or more octet string payloads. The algorithm MAY support using additional items provided by the holder for issuance such as blinded payloads, keys for replay prevention, etc. All algorithms MUST provide integrity protection for the issuer header and all payloads and MUST specify all digest and/or hash2curve methods used. 5.2. Confirm Performed by the holder to validate that the issued JWP is correctly formed and protected. Each algorithm MAY support using additional input items options, such as those sent to the issuer for issuance. After confirmation, an algorithm MAY return a modified JWP for serialized storage without the local state (such as with blinded payloads now unblinded). The algorithm MUST fully verify the issued proof value against the issuer protected header and all payloads. If given a presented JWP instead of an issued one, the confirm process MUST return an error. 5.3. Present Used to apply any selective disclosure choices and perform any unlinkability transformations, as well as to show binding. An algorithm MAY support additional input options from the requesting party, such as for predicate proofs and verifiable computation requests. Every algorithm MUST support the ability to hide any or all payloads. It MUST always include the issuer protected header unmodified in the presentation. The algorithm MUST replace the issued proof value and generate a new presented proof value. It also MUST include a new presentation protected header that provides replay protection. 5.4. Verify Performed by the verifier to verify the protected headers along with any disclosed payloads and/or assertions about them from the proving party, while also verifying they are the same payloads and ordering as witnessed by the issuer. The algorithm MUST verify the integrity of all disclosed payloads and MUST also verify the integrity of both the issuer and presentation protected headers. If the presented proof contains any assertions about the hidden payloads, the algorithm MUST also verify all of those assertions. It MAY support additional options, such as those sent to the holder to generate the presentation. If given an issued JWP for verification, the algorithm MUST return an error. 6. Algorithm Specifications This section defines how to use specific algorithms for JWPs. 6.1. Single Use The Single Use (SU) algorithm is based on composing multiple traditional asymmetric signatures into a single JWP proof. It enables a very simple form of selective disclosure without requiring any advanced cryptographic techniques. It does not support unlinkability if the same JWP is presented multiple times, therefore when privacy is required the holder will need to interact with the issuer again to receive new single-use JWPs (dynamically or in batches). 6.1.1. JWS Algorithm The Single Use algorithm is based on using multiple signatures to cover the individual payloads, all of which are generated with the same Asymmetric JSON Web Algorithm (JWA). The internal signing algorithm to use is part of the registration for a new Single Use algorithm identifier. The chosen JWA MUST be an asymmetric signing algorithm so that each signature can be verified without sharing any private values between the parties. This ensures that the verifier cannot brute force any non-disclosed payloads based only on their disclosed individual signatures. 6.1.2. Holder Setup In order to support the protection of a presentation by a holder to a verifier, the holder MUST use a Presentation Key during the issuance and the presentation of every Single Use JWP. This Presentation Key MUST be generated and used for only one JWP. The issuer MUST verify that the holder has possession of this key. The holder-issuer communication to exchange this information is out of scope of this specification, but can be accomplished by the holder using this key to generate a JWS that signs a value the issuer can verify as unique. 6.1.3. Issuer Setup To create a Single Use JWP, the issuer first generates a unique Ephemeral Key using the selected internal algorithm. This key-pair will be used to sign each of the payloads of a single JWP and then discarded. 6.1.4. Signing payloads Each individual payload is signed using the selected internal algorithm using the Ephemeral Key. 6.1.5. Issuer Protected Header The issuer's Ephemeral Key MUST be included in the issuer protected header via the Proof Key header parameter. The holder's Presentation Key MUST be included in issuer protected header via the Presentation Key header parameter. The issuer protected header is signed using the given JWA and the issuer's Stable Key. 6.1.6. Payloads Each JWP payload is processed in order and signed using the given JWA using the issuer's Ephemeral Key. 6.1.7. Proof The proof value is an octet string array. The first entry is the octet string of the issuer protected header signature, with an additional entry for each payload signature. 6.1.8. Presentation Protected Header To generate a new presentation, the holder first creates a presentation protected header that is specific to the verifier being presented to. This header MUST contain a parameter that both the holder and verifier trust as being unique and non-replayable. Use of the nonce header parameter is RECOMMENDED for this purpose. This specification registers the nonce header parameter for the presentation protected header that contains a string value either generated by the verifier or derived from values provided by the verifier. When present, the verifier MUST ensure the nonce value matches during verification. The presentation protected header MAY contain other header parameters that are either provided by the verifier or by the holder. These presentation header parameters SHOULD NOT contain values that are common across multiple presentations and SHOULD be unique to a single presentation and verifier. 6.1.9. Presentation | Editor's Note: The current definition here is incomplete, the | holder's signature needs to also incorporate the presented proof. The holder derives a new proof as part of presentation. The presented proof value will always contain the issuer's Stable Key signature for the issuer protected header as the first element. The second element of the presented proof is the holder's signature of the presentation protected header using the holder's presentation key. This signature is constructed using the same algorithm described in generating the issuer's signature over the issuer protected header. Signing only the presentation header with the Presentation Key is sufficient to protect the entire presentation since that key is private to the holder and only the contents of the presentation header are used for replay prevention. For each payload which is to be disclosed, the corresponding payload signature (from the issued JWP) is included in the proof. If a payload is omitted from the presented JWP, the signature value will NOT be includeed, and the presentation proof will have one less part. For example, if the second and fifth of five payloads are not disclosed, then the holder's derived proof would consist of the issuer's signature over the issuer protected header, the holder's signature over the holder's protected header, the ephemeral key signature over the first, third and fourth payloads. Since the individual signatures in the proof value are unique and remain unchanged across multiple presentations, a Single Use JWP SHOULD only be presented a single time to each verifier in order for the holder to remain unlinkable across multiple presentations. 6.1.10. Verification The verifier MUST verify the issuer protected header octets against the first part in the proof using the issuer's Stable Key. It MUST also verify the presentation protected header octets against the second part in the proof value using the holder's Presentation Key, as provided in the Presentation Key header parameter. With the headers verified, the Proof Key header parameter can then be used to verify each of the disclosed payload signatures. 6.1.11. JPA Registration The proposed JWP alg value is of the format "SU-" appended with the relevant JWS alg value for the chosen public and ephemeral key-pair algorithm, for example "SU-ES256". 6.2. BBS The BBS Signature Scheme [I-D.irtf-cfrg-bbs-signatures] is under active development within the CRFG. This algorithm supports both selective disclosure and unlinkability, enabling the holder to generate multiple presentations from one issued JWP without a verifier being able to correlate those presentations together based on the proof. 6.2.1. JPA Algorithms The BBS alg parameter value in the issuance protected header corresponds to a ciphersuite identifier of BBS_BLS12381G1_XMD:SHA- 256_SSWU_RO_. The BBS-PROOF alg parameter value in the presentation protected header corresponds to the same ciphersuite, but used in presentation form. 6.2.2. Key Format The key used for the BBS algorithm is an elliptic curve-based key pair, specifically against the G_2 subgroup of a pairing friendly curve. Additional details on key generation can be found in Section 3.4. The JWK and Cose Key Object representations of the key are detailed in [I-D.ietf-cose-bls-key-representations]. There is no additional holder presentation key necessary for presentation proofs. 6.2.3. Issuance Issuance is performed using the Sign operation from Section 3.5.1 of [I-D.irtf-cfrg-bbs-signatures]. This operation utilizes the issuer's BLS12-381 G2 key pair as SK and PK, along with desired protected header and payloads as the octets header and the octets array messages. The octets resulting from this operation form a single octet string in the issuance proof array, to be used along with the protected header and payloads to serialize the JWP. 6.2.4. Issuance Proof Verification Holder verification of the signature on issuance form is performed using the Verify operation from Section 3.5.2 of [I-D.irtf-cfrg-bbs-signatures]. This operation utilizes the issuer's public key as PK, the proof as signature, the protected header octets as header and the array of payload octets as messages. 6.2.5. Presentation Derivation of a presentation is done by the holder using the ProofGen operation from Section 3.5.3 of [I-D.irtf-cfrg-bbs-signatures]. This operation utilizes the issuer's public key as PK, the issuer protected header as header, the issuance proof as signature, the issuance payloads as messages, and the holder's presentation protected header as ph. The operation also takes a vector of indexes into messages, describing which payloads the holder wishes to disclose. All payloads are required for proof generation, but only these indicated payloads will be required to be disclosed for later proof verification. The output of this operation is the presentation proof, as a single octet string. Presentation serialization leverages the two protected headers and presentation proof, along with the disclosed payloads. Non-disclosed payloads are represented with the absent value of null in JSON serialization and a zero-length string in compact serialization. 6.2.6. Presentation Verification Verification of a presentation is done by the verifier using the ProofVerify operation from Section 3.5.4. This operation utilizes the issuer's public key as PK, the issuer protected header as header, the issuance proof as signature, the holder's presentation protected header as ph, and the payloads as disclosed_messages. In addition, the disclosed_indexes scalar array is calculated from the payloads provided. Values disclosed in the presented payloads have a zero-based index in this array, while the indices of absent payloads are omitted. 6.3. Message Authentication Code The Message Authentication Code (MAC) JPA uses a MAC to both generate ephemeral keys and compute authentication codes to protect the issuer header and each payload individually. Like the the Single Use algorithm family, it also does not support unlinkability if the same JWP is presented multiple times. and requires an individually issued JWP for each presentation in order to fully protect privacy. When compared to the JWS approach, using a MAC requires less computation but can result in potentially larger presentation proof values. The design is intentionally minimal and only involves using a single standardized MAC method instead of a mix of MAC/hash methods or a custom hash-based construct. It is able to use any published cryptographic MAC method such as HMAC [RFC2104] or KMAC (https://nvlpubs.nist.gov/nistpubs/SpecialPublications/ NIST.SP.800-185.pdf). It uses traditional public-key based signatures to verify the authenticity of the issuer and holder. 6.3.1. Holder Setup Prior to the issuer creating a new JWP, the issuer MUST have a presentation public key provided by the holder. The holder's presentation key MUST be included in the issuer's protected header using the Presentation Key header parameter. 6.3.2. Issuer Setup To use the MAC algorithm, the issuer must have a stable public key pair to perform signing. To start the issuance process, a single 32-byte random Shared Secret must first be generated. This value will be shared privately to the holder as part of the issuer's JWP proof value. The Shared Secret is used by both the issuer and holder as the MAC method's key to generate a new set of unique ephemeral keys. These keys are then used as the input to generate a MAC that protects each payload. 6.3.3. Combined MAC Representation The combined MAC representation is a single octet string representing the MAC values of the issuer protected header, along with each payload provided by the issuer. This representation is signed by the issuer, but not shared - parties will recreate this octet string and verify the signature to verify the integrity of supplied issuer protected header and the integrity of any disclosed payloads. The issuer protected header is included in this value as a MAC created using the fixed key "issuer_header" in UTF-8 encoded octets. The value is the issuer header JSON as a UTF-8 encoded octet string. A unique key is generated for each payload using a MAC, with the Shared Secret as the key and a value of "payload_X" as UTF-8 encoded octets, where "X" is replaced by the zero-based array index of the payload, for example "payload_0", "payload_1", etc. Each payload then itself has a corresponding MAC, using the above per-payload key and the payload octet string. The combined MAC representation is the octet string formed by the the concatentation of the issuer protected header MAC output, along with each payload MAC output. 6.3.4. Issuer Proof The issuer proof consists of two octet strings. The first octet string is the issuer signature over the combined MAC representation. The issuer signs the JWS using its stable public key, and a fixed header containing the alg associated with signing algorithm in use. jws_header = '{"alg":"ES256"}' The signature value of the JWS is extracted and base64url-decoded into an octet string. The second octet string is the Shared Secret used to generate the per-payload keys for the combined representation. 6.3.5. Presentation Protected Header See the JWS Presentation Protected Header (#presentation-protected- header) section. 6.3.6. Presentation Proof | Editor's Note: The current definition here is incomplete, the | holder's signature needs to also incorporate the presented proof. The first value in the presentation proof is the presentation signature. This is a signature over the presentation protected header, using the key specified by the Presentation Key header parameter in the issuer protected header. The second value is the issuer signature over the Combined MAC Representation provided with the issued form. The remaining values are used by the verifier to reconstruct the combined MAC representation without access to the Shared Secret. There is one value corresponding to each payload, whether it has been disclosed or not. If a payload is disclosed, the unique per-payload key derived from the shared secret is used as the payload's entry in the proof array. If a payload is not disclosed, the payload's MAC in the combined MAC representation is used as the payload's entry in the proof array. 6.3.7. Verification of the Presentation Proof The verifier must recreate the Combined MAC Representation from the presentation proof to verify integrity over the disclosed information. The issuer protected header MAC is recreated using the same mechanism described above. For each payload in the presentation: * If the payload is disclosed, then the presentation proof contains the unique per-payload key. The corresponding payload MAC can be computed by performing the MAC operation with this key and the corresponding payload. * If the payload is not disclosed, then the presentation proof contains the payload MAC, which can be used directly The concatenation of the octets of the issuer protected header MAC and each payload MAC forms the Combined MAC Representation. The issuer signature in the proof is then verified by converting these values to a JWS as described above, and verifying that JWS. 6.3.8. JPA Registration Proposed JWP alg value is of the format "MAC-" appended with a unique identifier for the set of MAC and signing algorithms used. Below are the initial registrations: * MAC-H256 uses HMAC SHA-256 as the MAC and ECDSA using P-256 and SHA-256 for the signatures * MAC-H384 uses HMAC SHA-384 as the MAC and ECDSA using P-384 and SHA-384 for the signatures * MAC-H512 uses HMAC SHA-512 as the MAC and ECDSA using P-521 and SHA-512 for the signatures * MAC-K25519 uses KMAC SHAKE128 as the MAC and EdDSA using Curve25519 for the signatures * MAC-K448 uses KMAC SHAKE256 as the MAC and EdDSA using Curve448 for the signatures * MAC-H256K uses HMAC SHA-256 as the MAC and ECDSA using secp256k1 and SHA-256 for the signatures 7. Security Considerations | Editor's Note: This will follow once the algorithms defined here | have become more stable. * Data minimization of the proof value * Unlinkability of the protected header contents 8. IANA Considerations The following registration procedure is used for all the registries established by this specification. Values are registered on a Specification Required [RFC5226] basis after a three-week review period on the jose-reg-review@ietf.org mailing list, on the advice of one or more Designated Experts. However, to allow for the allocation of values prior to publication, the Designated Experts may approve registration once they are satisfied that such a specification will be published. Registration requests sent to the mailing list for review should use an appropriate subject (e.g., "Request to register JWP algorithm: example"). Within the review period, the Designated Experts will either approve or deny the registration request, communicating this decision to the review list and IANA. Denials should include an explanation and, if applicable, suggestions as to how to make the request successful. Registration requests that are undetermined for a period longer than 21 days can be brought to the IESG's attention (using the iesg@ietf.org mailing list) for resolution. Criteria that should be applied by the Designated Experts include determining whether the proposed registration duplicates existing functionality, whether it is likely to be of general applicability or useful only for a single application, and whether the registration description is clear. IANA must only accept registry updates from the Designated Experts and should direct all requests for registration to the review mailing list. It is suggested that multiple Designated Experts be appointed who are able to represent the perspectives of different applications using this specification, in order to enable broadly informed review of registration decisions. In cases where a registration decision could be perceived as creating a conflict of interest for a particular Expert, that Expert should defer to the judgment of the other Experts. 8.1. JSON Web Proof Algorithms Registry This specification establishes the IANA "JSON Web Proof Algorithms" registry for values of the JWP alg (algorithm) parameter in JWP Header Parameters. The registry records the algorithm name, the algorithm description, the algorithm usage locations, the implementation requirements, the change controller, and a reference to the specification that defines it. The same algorithm name can be registered multiple times, provided that the sets of usage locations are disjoint. It is suggested that the length of the key be included in the algorithm name when multiple variations of algorithms are being registered that use keys of different lengths and the key lengths for each need to be fixed (for instance, because they will be created by key derivation functions). This allows readers of the JSON text to more easily make security decisions. The Designated Experts should perform reasonable due diligence that algorithms being registered either are currently considered cryptographically credible or are being registered as Deprecated or Prohibited. The implementation requirements of an algorithm may be changed over time as the cryptographic landscape evolves, for instance, to change the status of an algorithm to Deprecated or to change the status of an algorithm from Optional to Recommended+ or Required. Changes of implementation requirements are only permitted on a Specification Required basis after review by the Designated Experts, with the new specification defining the revised implementation requirements level. 8.1.1. Registration Template Algorithm Name: Brief descriptive name of the algorithm (e.g., Single-Use JWP using ES256.) Descriptive names may not match other registered names unless the Designated Experts state that there is a compelling reason to allow an exception. Algorithm JSON Label: The string label requested (e.g., SU-ES256). This label is a case-sensitive ASCII string. JSON Labels may not match other registered labels in a case-insensitive manner unless the Designated Experts state that there is a compelling reason to allow an exception. Algorithm CBOR Label: The integer label requested (e.g. 1). CBOR Labels may not match other registered labels unless the Designated Experts state that there is a compelling reason to allow an exception. Algorithm Description: Optional additional information clarifying the algorithm. This may be used for example to document additional chosen parameters. Algorithm Usage Location(s): The algorithm usage locations, which should be one or more of the values Issued or Presented. Other values may be used with the approval of a Designated Expert. JWP Implementation Requirements: The algorithm implementation requirements for JWP, which must be one the words Required, Recommended, Optional, Deprecated, or Prohibited. Optionally, the word can be followed by a + or -. The use of + indicates that the requirement strength is likely to be increased in a future version of the specification. The use of - indicates that the requirement strength is likely to be decreased in a future version of the specification. Any identifiers registered for algorithms that are otherwise unsuitable for direct use as JWP algorithms must be registered as Prohibited. Change Controller: For Standards Track RFCs, list the "IETF". For others, give the name of the responsible party. Other details (e.g., postal address, email address, home page URI) may also be included. Specification Document(s): Reference to the document or documents that specify the parameter, preferably including URIs that can be used to retrieve copies of the documents. An indication of the relevant sections may also be included but is not required. Algorithm Analysis Documents(s): References to a publication or publications in well-known cryptographic conferences, by national standards bodies, or by other authoritative sources analyzing the cryptographic soundness of the algorithm to be registered. The Designated Experts may require convincing evidence of the cryptographic soundness of a new algorithm to be provided with the registration request unless the algorithm is being registered as Deprecated or Prohibited. Having gone through working group and IETF review, the initial registrations made by this document are exempt from the need to provide this information. 8.1.2. Initial Registry Contents 8.1.2.1. Single-Use JWP using ES256 Algorithm * Algorithm Name: Single-Use JWP using ES256 * Algorithm JSON Label: SU-ES256 * Algorithm CBOR Label: 1 * Algorithm Usage Location(s): Issued, Presented * JWP Implementation Requirements: Recommended * Change Controller: IETF * Specification Document(s): Section 6.1.11 of this specification * Algorithm Analysis Documents(s): n/a 8.1.2.2. Single-Use JWP using ES384 Algorithm * Algorithm Name: Single-Use JWP using ES384 * Algorithm JSON Label: SU-ES384 * Algorithm CBOR Label: 2 * Algorithm Usage Location(s): Issued, Presented * JWP Implementation Requirements: Optional * Change Controller: IETF * Specification Document(s): Section 6.1.11 of this specification * Algorithm Analysis Documents(s): n/a 8.1.2.3. Single-Use JWP using ES512 Algorithm * Algorithm Name: Single-Use JWP using ES512 * Algorithm JSON Label: SU-ES512 * Algorithm CBOR Label: 3 * Algorithm Usage Location(s): Issued, Presented * JWP Implementation Requirements: Optional * Change Controller: IETF * Specification Document(s): Section 6.1.11 of this specification * Algorithm Analysis Documents(s): n/a 8.1.2.4. BBS using SHA-256 Algorithm * Algorithm Name: BBS using SHA-256 * Algorithm JSON Label: BBS * Algorithm CBOR Label: 4 * Algorithm Description: Corresponds to a ciphersuite identifier of BBS_BLS12381G1_XMD:SHA-256_SSWU_RO_H2G_HM2S_ * Algorithm Usage Location(s): Issued * JWP Implementation Requirements: Required * Change Controller: IETF * Specification Document(s): Section 6.2.1 of this specification * Algorithm Analysis Documents(s): n/a 8.1.2.5. BBS Proof using SHA-256 Algorithm * Algorithm Name: BBS Proof with SHA-256 * Algorithm JSON Label: BBS-PROOF * Algorithm CBOR Label: 5 * Algorithm Description: Corresponds to a ciphersuite identifier of BBS_BLS12381G1_XMD:SHA-256_SSWU_RO_H2G_HM2S_ * Algorithm Usage Location(s): Presented * JWP Implementation Requirements: Required * Change Controller: IETF * Specification Document(s): Section 6.2.1 of this specification * Algorithm Analysis Documents(s): n/a 8.1.2.6. MAC-H256 Algorithm * Algorithm Name: MAC-H256 * Algorithm JSON Label: MAC-H256 * Algorithm CBOR Label: 6 * Algorithm Description: MAC-H256 uses HMAC SHA-256 as the MAC, and ECDSA using P-256 and SHA-256 for the signatures * Algorithm Usage Location(s): Issued, Presented * JWP Implementation Requirements: Optional * Change Controller: IETF * Specification Document(s): Section 6.3.8 of this specification * Algorithm Analysis Documents(s): n/a 8.1.2.7. MAC-H384 Algorithm * Algorithm Name: MAC-H384 * Algorithm JSON Label: MAC-H384 * Algorithm CBOR Label: 7 * Algorithm Description: MAC-H384 uses HMAC SHA-384 as the MAC, and ECDSA using P-384 and SHA-384 for the signatures * Algorithm Usage Location(s): Issued, Presented * JWP Implementation Requirements: Optional * Change Controller: IETF * Specification Document(s): Section 6.3.8 of this specification * Algorithm Analysis Documents(s): n/a 8.1.2.8. MAC-H512 Algorithm * Algorithm Name: MAC-H512 * Algorithm JSON Label: MAC-H512 * Algorithm CBOR Label: 8 * Algorithm Description: MAC-H512 uses HMAC SHA-512 as the MAC, and ECDSA using P-521 and SHA-512 for the signatures * Algorithm Usage Location(s): Issued, Presented * JWP Implementation Requirements: Optional * Change Controller: IETF * Specification Document(s): Section 6.3.8 of this specification * Algorithm Analysis Documents(s): n/a 8.1.2.9. MAC-K25519 Algorithm * Algorithm Name: MAC-K25519 * Algorithm JSON Label: MAC-K25519 * Algorithm CBOR Label: 9 * Algorithm Description: MAC-K25519 uses KMAC SHAKE128 as the MAC, and EdDSA using Curve25519 for the signatures * Algorithm Usage Location(s): Issued, Presented * JWP Implementation Requirements: Optional * Change Controller: IETF * Specification Document(s): Section 6.3.8 of this specification * Algorithm Analysis Documents(s): n/a 8.1.2.10. MAC-K448 Algorithm * Algorithm Name: MAC-K448 * Algorithm JSON Label: MAC-K448 * Algorithm CBOR Label: 10 * Algorithm Description: MAC-K448 uses KMAC SHAKE256 as the MAC, and EdDSA using Curve448 for the signatures * Algorithm Usage Location(s): Issued, Presented * JWP Implementation Requirements: Optional * Change Controller: IETF * Specification Document(s): Section 6.3.8 of this specification * Algorithm Analysis Documents(s): n/a 8.1.2.11. MAC-H256K Algorithm * Algorithm Name: MAC-H256K * Algorithm JSON Label: MAC-H256K * Algorithm CBOR Label: 11 * Algorithm Description: MAC-H256K uses HMAC SHA-256 as the MAC, and ECDSA using secp256k1 and SHA-256 for the signatures * Algorithm Usage Location(s): Issued, Presented * JWP Implementation Requirements: Optional * Change Controller: IETF * Specification Document(s): Section 6.3.8 of this specification * Algorithm Analysis Documents(s): n/a 9. References 9.1. Normative References [I-D.ietf-jose-json-web-proof] Miller, J., Waite, D., and M. B. Jones, "JSON Web Proof", Work in Progress, Internet-Draft, draft-ietf-jose-json- web-proof-06, 16 September 2024, . [I-D.irtf-cfrg-bbs-signatures] Looker, T., Kalos, V., Whitehead, A., and M. Lodder, "The BBS Signature Scheme", Work in Progress, Internet-Draft, draft-irtf-cfrg-bbs-signatures-07, 23 September 2024, . 9.2. Informative References [I-D.ietf-cose-bls-key-representations] Looker, T. and M. B. Jones, "Barreto-Lynn-Scott Elliptic Curve Key Representations for JOSE and COSE", Work in Progress, Internet-Draft, draft-ietf-cose-bls-key- representations-05, 17 March 2024, . [RFC2104] Krawczyk, H., Bellare, M., and R. Canetti, "HMAC: Keyed- Hashing for Message Authentication", RFC 2104, DOI 10.17487/RFC2104, February 1997, . [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an IANA Considerations Section in RFCs", RFC 5226, DOI 10.17487/RFC5226, May 2008, . [RFC7515] Jones, M., Bradley, J., and N. Sakimura, "JSON Web Signature (JWS)", RFC 7515, DOI 10.17487/RFC7515, May 2015, . [RFC7518] Jones, M., "JSON Web Algorithms (JWA)", RFC 7518, DOI 10.17487/RFC7518, May 2015, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . [VC-DATA-MODEL-2.0] Sporny, M., Jr, T. T., Herman, I., Jones, M. B., and G. Cohen, "Verifiable Credentials Data Model 2.0", 27 December 2023, . Appendix A. Example JWPs The following examples use algorithms defined in JSON Proof Algorithms and also contain the keys used, so that implementations can validate these samples. A.1. Example Single-Use JWP This example uses the Single-Use Algorithm as defined in JSON Proof Algorithms to create a JSON Proof Token. It demonstrates how to apply selective disclosure using an array of traditional JWS-based signatures. Unlinkability is only achieved by using each JWP one time, as multiple uses are inherently linkable via the traditional ECDSA signature embedded in the proof. To begin, we need two asymmetric keys for Single Use: one that represents the JPT Issuer's stable key and the other is an ephemeral key generated by the Issuer just for this JWP. This is the Issuer's stable private key used in this example in the JWK format: { "kty": "EC", "crv": "P-256", "x": "2tCkcQagBT1ZdhzaoSQMRl9W3vxjTXWN0fG5f9zbtXI", "y": "plIKxDfuEq6x7ORlewFM4jx8T4o74fnE32pTOvFjVac", "d": "dA0Hod7NLSyt4mpu-nM1MB1hCJjFgzI5yGXBca6kiPg" } Figure 1: Issuer Private Key (es256) This is the ephemeral private key used in this example in the JWK format: { "kty": "EC", "crv": "P-256", "x": "0wDXp6CZoO60FS2uuy3oLY4be5Rz2BXAwG572HCU1Yg", "y": "xJcvArj4uz04OiH9FCszmfRhyHRCfOOJriQt-8Yi2eQ", "d": "UbeuNiJo0YRKG4hYluWJuwycqWzwL6YjTECqHkJwTPY" } Figure 2: Issuer Ephemeral Private Key (es256) This is the Holder's presentation private key used in this example in the JWK format: { "kty": "EC", "crv": "P-256", "x": "VtdIpLqMdetTBmpR0Mq5aPGuCQdw_zJmZBaKd77e6dU", "y": "TqEQIqwgizMqO8O5ZVebIbM_3cgs8M2YDPbwbKTCoKI", "d": "JuxIPs6wqL_Z97QTY-L-toptDiA6dglzBoowtKu4wjQ" } Figure 3: Holder Presentation Private Key The JWP Protected Header declares that the data structure is a JPT and the JWP Proof Input is secured using the Single-Use ECDSA algorithm with the P-256 curve and SHA-256 digest. It also includes the ephemeral public key, the Holder's presentation public key and list of claims used for this JPT. { "alg": "SU-ES256", "typ": "JPT", "iss": "https://issuer.example", "claims": [ "iat", "exp", "family_name", "given_name", "email", "address", "age_over_21" ], "proof_key": { "kty": "EC", "crv": "P-256", "x": "0wDXp6CZoO60FS2uuy3oLY4be5Rz2BXAwG572HCU1Yg", "y": "xJcvArj4uz04OiH9FCszmfRhyHRCfOOJriQt-8Yi2eQ", "d": "UbeuNiJo0YRKG4hYluWJuwycqWzwL6YjTECqHkJwTPY" }, "presentation_key": { "kty": "EC", "crv": "P-256", "x": "VtdIpLqMdetTBmpR0Mq5aPGuCQdw_zJmZBaKd77e6dU", "y": "TqEQIqwgizMqO8O5ZVebIbM_3cgs8M2YDPbwbKTCoKI", "d": "JuxIPs6wqL_Z97QTY-L-toptDiA6dglzBoowtKu4wjQ" } } Figure 4: Issuer Protected header (es256) The JWP Protected Header JSON is serialized (without the above whitespace added for readability) and uses UTF-8 encoding to convert into an octet string. This gives: eyJhbGciOiJTVS1FUzI1NiIsInR5cCI6IkpQVCIsImlzcyI6Imh0dHBzOi8vaXNzdWVyL mV4YW1wbGUiLCJjbGFpbXMiOlsiaWF0IiwiZXhwIiwiZmFtaWx5X25hbWUiLCJnaXZlbl 9uYW1lIiwiZW1haWwiLCJhZGRyZXNzIiwiYWdlX292ZXJfMjEiXSwicHJvb2Zfa2V5Ijp 7Imt0eSI6IkVDIiwiY3J2IjoiUC0yNTYiLCJ4IjoiMHdEWHA2Q1pvTzYwRlMydXV5M29M WTRiZTVSejJCWEF3RzU3MkhDVTFZZyIsInkiOiJ4SmN2QXJqNHV6MDRPaUg5RkNzem1mU mh5SFJDZk9PSnJpUXQtOFlpMmVRIiwiZCI6IlViZXVOaUpvMFlSS0c0aFlsdVdKdXd5Y3 FXendMNllqVEVDcUhrSndUUFkifSwicHJlc2VudGF0aW9uX2tleSI6eyJrdHkiOiJFQyI sImNydiI6IlAtMjU2IiwieCI6IlZ0ZElwTHFNZGV0VEJtcFIwTXE1YVBHdUNRZHdfekpt WkJhS2Q3N2U2ZFUiLCJ5IjoiVHFFUUlxd2dpek1xTzhPNVpWZWJJYk1fM2NnczhNMllEU GJ3YktUQ29LSSIsImQiOiJKdXhJUHM2d3FMX1o5N1FUWS1MLXRvcHREaUE2ZGdsekJvb3 d0S3U0d2pRIn19 Figure 5: Encoded Issuer Protected Header (es256, base64url-encoded) The Single Use algorithm utilizes multiple individual JWS Signatures. Each signature value is generated by creating a JWS with a single Protected Header with the associated alg value. In this example, the fixed header used for each JWS is the serialized JSON Object {"alg":"ES256"}. This protected header will be used to generate a signature over each corresponding payload in the JWP. The corresponding octet value in the proof is the octet string (base64url-decoded) value of the signature. The final proof value from the Issuer is an array with the octets of the header signature, followed by entries for each payload signature. The resulting JSON serialized JPT using the above examples is: { "issuer": "eyJhbGciOiJTVS1FUzI1NiIsInR5cCI6IkpQVCIsImlzcyI6Imh0dHBz Oi8vaXNzdWVyLmV4YW1wbGUiLCJjbGFpbXMiOlsiaWF0IiwiZXhwIiwiZmFtaW x5X25hbWUiLCJnaXZlbl9uYW1lIiwiZW1haWwiLCJhZGRyZXNzIiwiYWdlX292 ZXJfMjEiXSwicHJvb2Zfa2V5Ijp7Imt0eSI6IkVDIiwiY3J2IjoiUC0yNTYiLC J4IjoiMHdEWHA2Q1pvTzYwRlMydXV5M29MWTRiZTVSejJCWEF3RzU3MkhDVTFZ ZyIsInkiOiJ4SmN2QXJqNHV6MDRPaUg5RkNzem1mUmh5SFJDZk9PSnJpUXQtOF lpMmVRIiwiZCI6IlViZXVOaUpvMFlSS0c0aFlsdVdKdXd5Y3FXendMNllqVEVD cUhrSndUUFkifSwicHJlc2VudGF0aW9uX2tleSI6eyJrdHkiOiJFQyIsImNydi I6IlAtMjU2IiwieCI6IlZ0ZElwTHFNZGV0VEJtcFIwTXE1YVBHdUNRZHdfekpt WkJhS2Q3N2U2ZFUiLCJ5IjoiVHFFUUlxd2dpek1xTzhPNVpWZWJJYk1fM2Nncz hNMllEUGJ3YktUQ29LSSIsImQiOiJKdXhJUHM2d3FMX1o5N1FUWS1MLXRvcHRE aUE2ZGdsekJvb3d0S3U0d2pRIn19", "payloads": [ "MTcxNDUyMTYwMA", "MTcxNzE5OTk5OQ", "IkRvZSI", "IkpheSI", "ImpheWRvZUBleGFtcGxlLm9yZyI", "eyJmb3JtYXR0ZWQiOiIxMjM0IE1haW4gU3QuXG5Bbnl0b3duLCBDQSAxMjM0NVxu VVNBIiwic3RyZWV0X2FkZHJlc3MiOiIxMjM0IE1haW4gU3QuIiwibG9jYWxpdH kiOiJBbnl0b3duIiwicmVnaW9uIjoiQ0EiLCJwb3N0YWxfY29kZSI6MTIzNDUs ImNvdW50cnkiOiJVU0EifQ", "dHJ1ZQ" ], "proof": [ "iNMnDLoLB0fFDux9hw0uS3yCXkhqRXiMrQm1F2hTkjjxrkYS-PLMoAo2T_GBkBA3 xgjguudpBMtXkpjeZ3hV9A", "bW5FG068XlHkI5jXAg3k983Eakn5WhimW1yN3YGLvYziEObmddDJ2G4VohtnYJBv mhY6ZgOlcRlS-jfIwnDsRw", "TKl3EmZZLEF4tq-E5buhio7jcGSNJB9yjVamxAlsd-odlYApU2nE4GY_ImJHndpB kxOt4FyhjWxL4aRxAxG-hg", "kw9SLT58g9OLAlixGAgZGsq-31Z8i3JzJU5ADgCSdl2G6l56GKBXtza43xe9NxLN 2ZGfGUCgoCgtac1wD1WYQA", "YtJwmY_GAZ_BxukPTF25Cp7ZUrVBV7y40GGEstKTX-CvuJwdUEKl4owE55mDcoMW uBl5XijAg0aAQAbyuzA5Zg", "AGA7cungTq_0ZVl_DBc7LBwolrtk1hcKX2m4h4hVZd4V3HZrDSF9MUHEZHunB6UP qRaB2uv6aHFk-M154WlDqA", "PduEJ5jxQbyTagXNeJ5aE1sLRIyv_MjPjb_P9JnsQj65TAwg0P31TXZLb283BIuS vvzG4vq-dc1fAWiDtCsFXQ", "qdabwX9ImLroTZR8i7CNh7HrlS16qfHYWIkZNHIgSqmWKF6hYhUiw9uplirVpH1q xAhkLl54CPvf5n6IyZI9Pw" ] } Figure 6: Issued JWP in JSON Serialization (es256) The compact serialization of the same JPT is: eyJhbGciOiJTVS1FUzI1NiIsInR5cCI6IkpQVCIsImlzcyI6Imh0dHBzOi8vaXNzdWVyL mV4YW1wbGUiLCJjbGFpbXMiOlsiaWF0IiwiZXhwIiwiZmFtaWx5X25hbWUiLCJnaXZlbl 9uYW1lIiwiZW1haWwiLCJhZGRyZXNzIiwiYWdlX292ZXJfMjEiXSwicHJvb2Zfa2V5Ijp 7Imt0eSI6IkVDIiwiY3J2IjoiUC0yNTYiLCJ4IjoiMHdEWHA2Q1pvTzYwRlMydXV5M29M WTRiZTVSejJCWEF3RzU3MkhDVTFZZyIsInkiOiJ4SmN2QXJqNHV6MDRPaUg5RkNzem1mU mh5SFJDZk9PSnJpUXQtOFlpMmVRIiwiZCI6IlViZXVOaUpvMFlSS0c0aFlsdVdKdXd5Y3 FXendMNllqVEVDcUhrSndUUFkifSwicHJlc2VudGF0aW9uX2tleSI6eyJrdHkiOiJFQyI sImNydiI6IlAtMjU2IiwieCI6IlZ0ZElwTHFNZGV0VEJtcFIwTXE1YVBHdUNRZHdfekpt WkJhS2Q3N2U2ZFUiLCJ5IjoiVHFFUUlxd2dpek1xTzhPNVpWZWJJYk1fM2NnczhNMllEU GJ3YktUQ29LSSIsImQiOiJKdXhJUHM2d3FMX1o5N1FUWS1MLXRvcHREaUE2ZGdsekJvb3 d0S3U0d2pRIn19.MTcxNDUyMTYwMA~MTcxNzE5OTk5OQ~IkRvZSI~IkpheSI~ImpheWRv ZUBleGFtcGxlLm9yZyI~eyJmb3JtYXR0ZWQiOiIxMjM0IE1haW4gU3QuXG5Bbnl0b3duL CBDQSAxMjM0NVxuVVNBIiwic3RyZWV0X2FkZHJlc3MiOiIxMjM0IE1haW4gU3QuIiwibG 9jYWxpdHkiOiJBbnl0b3duIiwicmVnaW9uIjoiQ0EiLCJwb3N0YWxfY29kZSI6MTIzNDU sImNvdW50cnkiOiJVU0EifQ~dHJ1ZQ.iNMnDLoLB0fFDux9hw0uS3yCXkhqRXiMrQm1F2 hTkjjxrkYS-PLMoAo2T_GBkBA3xgjguudpBMtXkpjeZ3hV9A~bW5FG068XlHkI5jXAg3k 983Eakn5WhimW1yN3YGLvYziEObmddDJ2G4VohtnYJBvmhY6ZgOlcRlS-jfIwnDsRw~TK l3EmZZLEF4tq-E5buhio7jcGSNJB9yjVamxAlsd-odlYApU2nE4GY_ImJHndpBkxOt4Fy hjWxL4aRxAxG-hg~kw9SLT58g9OLAlixGAgZGsq-31Z8i3JzJU5ADgCSdl2G6l56GKBXt za43xe9NxLN2ZGfGUCgoCgtac1wD1WYQA~YtJwmY_GAZ_BxukPTF25Cp7ZUrVBV7y40GG EstKTX-CvuJwdUEKl4owE55mDcoMWuBl5XijAg0aAQAbyuzA5Zg~AGA7cungTq_0ZVl_D Bc7LBwolrtk1hcKX2m4h4hVZd4V3HZrDSF9MUHEZHunB6UPqRaB2uv6aHFk-M154WlDqA ~PduEJ5jxQbyTagXNeJ5aE1sLRIyv_MjPjb_P9JnsQj65TAwg0P31TXZLb283BIuSvvzG 4vq-dc1fAWiDtCsFXQ~qdabwX9ImLroTZR8i7CNh7HrlS16qfHYWIkZNHIgSqmWKF6hYh Uiw9uplirVpH1qxAhkLl54CPvf5n6IyZI9Pw Figure 7: Issued JWP in Compact Serialization (es256) To present this JPT, we first use the following presentation header with a nonce (provided by the Verifier): { "alg": "SU-ES256", "aud": "https://recipient.example.com", "nonce": "KZPGrOOm3m3gotj8s2fChQsoS-_YcIbo_WCQSuPYgzs" } Figure 8: Presentation Header This header is serialized without whitespace and UTF-8 encoded into an octet string. This gives: eyJhbGciOiJTVS1FUzI1NiIsImF1ZCI6Imh0dHBzOi8vcmVjaXBpZW50LmV4YW1wbGUuY 29tIiwibm9uY2UiOiJLWlBHck9PbTNtM2dvdGo4czJmQ2hRc29TLV9ZY0lib19XQ1FTdV BZZ3pzIn0 Figure 9: Presentation Header (base64url-encoded) When signed with the holder's presentation key, the resulting signature are: R44Aw4U0m-q8VUP2K-jfwcDjRA-ylHBlgoxIMtzcqIzfNDbjBuuPzxb_2FrG5-QdHk-7I ztZJLam-pbSefz4sw | Figure: Holder Proof-of-Possession (base64url-encoded) Then by applying selective disclosure of only the given name and age claims (family name and email hidden), we get the following presented JPT: { "presentation": "eyJhbGciOiJTVS1FUzI1NiIsImF1ZCI6Imh0dHBzOi8vcmVjaX BpZW50LmV4YW1wbGUuY29tIiwibm9uY2UiOiJLWlBHck9PbTNtM2dvdGo4czJm Q2hRc29TLV9ZY0lib19XQ1FTdVBZZ3pzIn0", "issuer": "eyJhbGciOiJTVS1FUzI1NiIsInR5cCI6IkpQVCIsImlzcyI6Imh0dHBz Oi8vaXNzdWVyLmV4YW1wbGUiLCJjbGFpbXMiOlsiaWF0IiwiZXhwIiwiZmFtaW x5X25hbWUiLCJnaXZlbl9uYW1lIiwiZW1haWwiLCJhZGRyZXNzIiwiYWdlX292 ZXJfMjEiXSwicHJvb2Zfa2V5Ijp7Imt0eSI6IkVDIiwiY3J2IjoiUC0yNTYiLC J4IjoiMHdEWHA2Q1pvTzYwRlMydXV5M29MWTRiZTVSejJCWEF3RzU3MkhDVTFZ ZyIsInkiOiJ4SmN2QXJqNHV6MDRPaUg5RkNzem1mUmh5SFJDZk9PSnJpUXQtOF lpMmVRIiwiZCI6IlViZXVOaUpvMFlSS0c0aFlsdVdKdXd5Y3FXendMNllqVEVD cUhrSndUUFkifSwicHJlc2VudGF0aW9uX2tleSI6eyJrdHkiOiJFQyIsImNydi I6IlAtMjU2IiwieCI6IlZ0ZElwTHFNZGV0VEJtcFIwTXE1YVBHdUNRZHdfekpt WkJhS2Q3N2U2ZFUiLCJ5IjoiVHFFUUlxd2dpek1xTzhPNVpWZWJJYk1fM2Nncz hNMllEUGJ3YktUQ29LSSIsImQiOiJKdXhJUHM2d3FMX1o5N1FUWS1MLXRvcHRE aUE2ZGdsekJvb3d0S3U0d2pRIn19", "payloads": [ "MTcxNDUyMTYwMA", "MTcxNzE5OTk5OQ", "IkRvZSI", "IkpheSI", "ImpheWRvZUBleGFtcGxlLm9yZyI", "eyJmb3JtYXR0ZWQiOiIxMjM0IE1haW4gU3QuXG5Bbnl0b3duLCBDQSAxMjM0NVxu VVNBIiwic3RyZWV0X2FkZHJlc3MiOiIxMjM0IE1haW4gU3QuIiwibG9jYWxpdH kiOiJBbnl0b3duIiwicmVnaW9uIjoiQ0EiLCJwb3N0YWxfY29kZSI6MTIzNDUs ImNvdW50cnkiOiJVU0EifQ", "dHJ1ZQ", null, null ], "proof": [ "iNMnDLoLB0fFDux9hw0uS3yCXkhqRXiMrQm1F2hTkjjxrkYS-PLMoAo2T_GBkBA3 xgjguudpBMtXkpjeZ3hV9A", "R44Aw4U0m-q8VUP2K-jfwcDjRA-ylHBlgoxIMtzcqIzfNDbjBuuPzxb_2FrG5-Qd Hk-7IztZJLam-pbSefz4sw", "bW5FG068XlHkI5jXAg3k983Eakn5WhimW1yN3YGLvYziEObmddDJ2G4VohtnYJBv mhY6ZgOlcRlS-jfIwnDsRw", "TKl3EmZZLEF4tq-E5buhio7jcGSNJB9yjVamxAlsd-odlYApU2nE4GY_ImJHndpB kxOt4FyhjWxL4aRxAxG-hg", "kw9SLT58g9OLAlixGAgZGsq-31Z8i3JzJU5ADgCSdl2G6l56GKBXtza43xe9NxLN 2ZGfGUCgoCgtac1wD1WYQA", "YtJwmY_GAZ_BxukPTF25Cp7ZUrVBV7y40GGEstKTX-CvuJwdUEKl4owE55mDcoMW uBl5XijAg0aAQAbyuzA5Zg", "AGA7cungTq_0ZVl_DBc7LBwolrtk1hcKX2m4h4hVZd4V3HZrDSF9MUHEZHunB6UP qRaB2uv6aHFk-M154WlDqA" ] } | Figure: Final Presentation in JSON Serialization And also in compact serialization: eyJhbGciOiJTVS1FUzI1NiIsImF1ZCI6Imh0dHBzOi8vcmVjaXBpZW50LmV4YW1wbGUuY 29tIiwibm9uY2UiOiJLWlBHck9PbTNtM2dvdGo4czJmQ2hRc29TLV9ZY0lib19XQ1FTdV BZZ3pzIn0.eyJhbGciOiJTVS1FUzI1NiIsInR5cCI6IkpQVCIsImlzcyI6Imh0dHBzOi8 vaXNzdWVyLmV4YW1wbGUiLCJjbGFpbXMiOlsiaWF0IiwiZXhwIiwiZmFtaWx5X25hbWUi LCJnaXZlbl9uYW1lIiwiZW1haWwiLCJhZGRyZXNzIiwiYWdlX292ZXJfMjEiXSwicHJvb 2Zfa2V5Ijp7Imt0eSI6IkVDIiwiY3J2IjoiUC0yNTYiLCJ4IjoiMHdEWHA2Q1pvTzYwRl MydXV5M29MWTRiZTVSejJCWEF3RzU3MkhDVTFZZyIsInkiOiJ4SmN2QXJqNHV6MDRPaUg 5RkNzem1mUmh5SFJDZk9PSnJpUXQtOFlpMmVRIiwiZCI6IlViZXVOaUpvMFlSS0c0aFls dVdKdXd5Y3FXendMNllqVEVDcUhrSndUUFkifSwicHJlc2VudGF0aW9uX2tleSI6eyJrd HkiOiJFQyIsImNydiI6IlAtMjU2IiwieCI6IlZ0ZElwTHFNZGV0VEJtcFIwTXE1YVBHdU NRZHdfekptWkJhS2Q3N2U2ZFUiLCJ5IjoiVHFFUUlxd2dpek1xTzhPNVpWZWJJYk1fM2N nczhNMllEUGJ3YktUQ29LSSIsImQiOiJKdXhJUHM2d3FMX1o5N1FUWS1MLXRvcHREaUE2 ZGdsekJvb3d0S3U0d2pRIn19.MTcxNDUyMTYwMA~MTcxNzE5OTk5OQ~IkRvZSI~IkpheS I~ImpheWRvZUBleGFtcGxlLm9yZyI~eyJmb3JtYXR0ZWQiOiIxMjM0IE1haW4gU3QuXG5 Bbnl0b3duLCBDQSAxMjM0NVxuVVNBIiwic3RyZWV0X2FkZHJlc3MiOiIxMjM0IE1haW4g U3QuIiwibG9jYWxpdHkiOiJBbnl0b3duIiwicmVnaW9uIjoiQ0EiLCJwb3N0YWxfY29kZ SI6MTIzNDUsImNvdW50cnkiOiJVU0EifQ~dHJ1ZQ~~.iNMnDLoLB0fFDux9hw0uS3yCXk hqRXiMrQm1F2hTkjjxrkYS-PLMoAo2T_GBkBA3xgjguudpBMtXkpjeZ3hV9A~R44Aw4U0 m-q8VUP2K-jfwcDjRA-ylHBlgoxIMtzcqIzfNDbjBuuPzxb_2FrG5-QdHk-7IztZJLam- pbSefz4sw~bW5FG068XlHkI5jXAg3k983Eakn5WhimW1yN3YGLvYziEObmddDJ2G4Voht nYJBvmhY6ZgOlcRlS-jfIwnDsRw~TKl3EmZZLEF4tq-E5buhio7jcGSNJB9yjVamxAlsd -odlYApU2nE4GY_ImJHndpBkxOt4FyhjWxL4aRxAxG-hg~kw9SLT58g9OLAlixGAgZGsq -31Z8i3JzJU5ADgCSdl2G6l56GKBXtza43xe9NxLN2ZGfGUCgoCgtac1wD1WYQA~YtJwm Y_GAZ_BxukPTF25Cp7ZUrVBV7y40GGEstKTX-CvuJwdUEKl4owE55mDcoMWuBl5XijAg0 aAQAbyuzA5Zg~AGA7cungTq_0ZVl_DBc7LBwolrtk1hcKX2m4h4hVZd4V3HZrDSF9MUHE ZHunB6UPqRaB2uv6aHFk-M154WlDqA | Figure: Final Presentation in Compact Serialization A.2. Example BBS JWP The following example uses the BBS algorithm. This is the Issuer's stable private key in the JWK format: { "kty": "EC2", "alg": "BBS", "use": "proof", "crv": "BLS12381G2", "x": "Fs2Bf5yIhO3OfJRdq8PJwoRRK9B76Tuk2Cjn1pevYG6DdCW_9JJEfP3yKd_BC 7FiC8JBUdN9-bkpU_mjdc7YjxyahMImsyw1ew74EC7bOlA2eFWWhTd9Vf-95Lz WfdYj", "y": "EydWzY6ZYUEw9o1MwMoiy_nJL-Ihggq9yR0WoGkZ64IhJp1qg9gYuLbFKrOZd sllAbkgItIY5JjIO3PhOWGhemMZ-FfCGE1DOO1yBzrll-3zR-J1QNhpVwGXndN 1RU8t", "d": "X-45ln1w3D3ebBK4uxJAqA-93t-Sro8tafGnZRb24cY" } Figure 10: BBS private key in JWK format There is no additional holder key necessary for presentation proofs. For the following protected header and array of payloads: { "kid": "HjfcpyjuZQ-O8Ye2hQnNbT9RbbnrobptdnExR0DUjU8", "alg": "BBS" } Figure 11: Example issuer protected header [ 1714521600, 1717199999, "Doe", "Jay", "jaydoe@example.org", { "formatted": "1234 Main St.\nAnytown, CA 12345\nUSA", "street_address": "1234 Main St.", "locality": "Anytown", "region": "CA", "postal_code": 12345, "country": "USA" }, true ] Figure 12: Example issuer payloads (as members of a JSON array) These components are signed using the private issuer key previously given, which is then representable in the following serializations: { "issuer": "eyJraWQiOiJIamZjcHlqdVpRLU84WWUyaFFuTmJUOVJiYm5yb2JwdGRu RXhSMERValU4IiwiYWxnIjoiQkJTIn0", "payloads": [ "MTcxNDUyMTYwMA", "MTcxNzE5OTk5OQ", "IkRvZSI", "IkpheSI", "ImpheWRvZUBleGFtcGxlLm9yZyI", "eyJmb3JtYXR0ZWQiOiIxMjM0IE1haW4gU3QuXG5Bbnl0b3duLCBDQSAxMjM0NVxu VVNBIiwic3RyZWV0X2FkZHJlc3MiOiIxMjM0IE1haW4gU3QuIiwibG9jYWxpdH kiOiJBbnl0b3duIiwicmVnaW9uIjoiQ0EiLCJwb3N0YWxfY29kZSI6MTIzNDUs ImNvdW50cnkiOiJVU0EifQ", "dHJ1ZQ" ], "proof": [ "gYq3jxQjMLu_LxQ3vH3gQQQwvcsqHmTGHZwoNNm5MeKF9gLa_7bFs6D0xaNq_tGb cL-NBRqTPOhD7ADA2yNf8hD7seHMEMpbtK81JZb96uI" ] } Figure 13: Issued JWP (JSON serialization) eyJraWQiOiJIamZjcHlqdVpRLU84WWUyaFFuTmJUOVJiYm5yb2JwdGRuRXhSMERValU4I iwiYWxnIjoiQkJTIn0.MTcxNDUyMTYwMA~MTcxNzE5OTk5OQ~IkRvZSI~IkpheSI~Imph eWRvZUBleGFtcGxlLm9yZyI~eyJmb3JtYXR0ZWQiOiIxMjM0IE1haW4gU3QuXG5Bbnl0b 3duLCBDQSAxMjM0NVxuVVNBIiwic3RyZWV0X2FkZHJlc3MiOiIxMjM0IE1haW4gU3QuIi wibG9jYWxpdHkiOiJBbnl0b3duIiwicmVnaW9uIjoiQ0EiLCJwb3N0YWxfY29kZSI6MTI zNDUsImNvdW50cnkiOiJVU0EifQ~dHJ1ZQ.gYq3jxQjMLu_LxQ3vH3gQQQwvcsqHmTGHZ woNNm5MeKF9gLa_7bFs6D0xaNq_tGbcL-NBRqTPOhD7ADA2yNf8hD7seHMEMpbtK81JZb 96uI Figure 14: Issued JWP (compact serialization) For a presentation with the following presentation header: { "alg": "BBS-PROOF", "aud": "https://recipient.example.com", "nonce": "wrmBRkKtXjQ" } Figure 15: Holder Presentation Header The holder decides to share all information other than the email address, and generates a proof. That proof is represented in the following serializations: { "presentation": "eyJhbGciOiJCQlMtUFJPT0YiLCJhdWQiOiJodHRwczovL3JlY2 lwaWVudC5leGFtcGxlLmNvbSIsIm5vbmNlIjoid3JtQlJrS3RYalEifQ", "issuer": "eyJraWQiOiJIamZjcHlqdVpRLU84WWUyaFFuTmJUOVJiYm5yb2JwdGRu RXhSMERValU4IiwiYWxnIjoiQkJTIn0", "payloads": [ "MTcxNDUyMTYwMA", "MTcxNzE5OTk5OQ", "IkRvZSI", "IkpheSI", null, null, null ], "proof": [ "jJtrd_zOFgjy_WgjJiv4KXXFxRlcgAodGFqORovW_JSNlqRTDIu2RGbbOHz66KXh gOF71-1ZuB5wa4FODeEqB56KfmPQKNYOEfZ8SvXiFFVjU-8jygjiILSuT4ylw6 Ecl_LdmDU2Oh-LcQvWJdLrMHms-aSpOMvqDYQeTjGo38zlVv4jeszte0iTqe2n PLgKBdYCGJ6kYVJ8YDL0Qt0UpAeBhIssYVpOwoUQS5ismTg2Ba2ImmlojpEs0c EqD1F0iCf9GbAnZ_H0N2sUnJDJEQR4uIcvc6qmX7repkKpM4_AGTbemwDaQzEk p5JiOWNfEGBskqiXsmDBrfnim4DN434ByWu8cTeprMn6tF7a3BZm0JkGt1wrya Qsi9cg5iPHeK1tybOYvqtiN3MMqpIaiTKGwKWyR1xj5BpnzeTmhCVxAjXc57Jg faKHOW3ILPBrKMcN19A3ifZ8aJscr_wdvjrHJLjycUu9ubmyYsdHRI0" ] } Figure 16: Presentation JWP (JSON serialization) eyJhbGciOiJCQlMtUFJPT0YiLCJhdWQiOiJodHRwczovL3JlY2lwaWVudC5leGFtcGxlL mNvbSIsIm5vbmNlIjoid3JtQlJrS3RYalEifQ.eyJraWQiOiJIamZjcHlqdVpRLU84WWU yaFFuTmJUOVJiYm5yb2JwdGRuRXhSMERValU4IiwiYWxnIjoiQkJTIn0.MTcxNDUyMTYw MA~MTcxNzE5OTk5OQ~IkRvZSI~IkpheSI~~~.jJtrd_zOFgjy_WgjJiv4KXXFxRlcgAod GFqORovW_JSNlqRTDIu2RGbbOHz66KXhgOF71-1ZuB5wa4FODeEqB56KfmPQKNYOEfZ8S vXiFFVjU-8jygjiILSuT4ylw6Ecl_LdmDU2Oh-LcQvWJdLrMHms-aSpOMvqDYQeTjGo38 zlVv4jeszte0iTqe2nPLgKBdYCGJ6kYVJ8YDL0Qt0UpAeBhIssYVpOwoUQS5ismTg2Ba2 ImmlojpEs0cEqD1F0iCf9GbAnZ_H0N2sUnJDJEQR4uIcvc6qmX7repkKpM4_AGTbemwDa QzEkp5JiOWNfEGBskqiXsmDBrfnim4DN434ByWu8cTeprMn6tF7a3BZm0JkGt1wryaQsi 9cg5iPHeK1tybOYvqtiN3MMqpIaiTKGwKWyR1xj5BpnzeTmhCVxAjXc57JgfaKHOW3ILP BrKMcN19A3ifZ8aJscr_wdvjrHJLjycUu9ubmyYsdHRI0 Figure 17: Presentation JWP (compact serialization) A.3. Example MAC JWP The following example uses the MAC-H256 algorithm. This is the Issuer's stable private key in the JWK format: { "kty": "EC", "crv": "P-256", "x": "2tCkcQagBT1ZdhzaoSQMRl9W3vxjTXWN0fG5f9zbtXI", "y": "plIKxDfuEq6x7ORlewFM4jx8T4o74fnE32pTOvFjVac", "d": "dA0Hod7NLSyt4mpu-nM1MB1hCJjFgzI5yGXBca6kiPg" } Figure 18: Issuer private key This is the Issuer's ephemerally generated shared secret: "pYCfsEt6lN7Yw8HKaBugY-rIWYEx87QZuVzAqVxZJww" Figure 19: Shared Secret This is the Holder's presentation private key in the JWK format: { "kty": "EC", "crv": "P-256", "x": "VtdIpLqMdetTBmpR0Mq5aPGuCQdw_zJmZBaKd77e6dU", "y": "TqEQIqwgizMqO8O5ZVebIbM_3cgs8M2YDPbwbKTCoKI", "d": "JuxIPs6wqL_Z97QTY-L-toptDiA6dglzBoowtKu4wjQ" } Figure 20: Holder private key For the following protected header and array of payloads: { "alg": "MAC-H256", "typ": "JPT", "iss": "https://issuer.example", "claims": [ "iat", "exp", "family_name", "given_name", "email", "address", "age_over_21" ], "presentation_key": { "kty": "EC", "crv": "P-256", "use": "sign", "x": "VtdIpLqMdetTBmpR0Mq5aPGuCQdw_zJmZBaKd77e6dU", "y": "TqEQIqwgizMqO8O5ZVebIbM_3cgs8M2YDPbwbKTCoKI" } } Figure 21: Example issuer protected header [ 1714521600, 1717199999, "Doe", "Jay", "jaydoe@example.org", { "formatted": "1234 Main St.\nAnytown, CA 12345\nUSA", "street_address": "1234 Main St.", "locality": "Anytown", "region": "CA", "postal_code": 12345, "country": "USA" }, true ] Figure 22: Example issuer payloads (as members of a JSON array) The first MAC is generated using the key issuer_header and a value of the issuer protected header as a UTF-8 encoded octet string. This results in the following MAC: OJZXUWATx1m9t1_8bMfjXA2bnLlwAUpUENEENGzVwtw Figure 23: Issuer MAC of protected header (base64url-encoded) The issuer generates an array of derived keys with one for each payload by using the shared secret as the key, and the index of the payload (as payload_{n} in UTF-8 encoded octets) as the input in a HMAC operation. This results in the following set of derived keys: [ "bm8tJeEw895F8kFtaja_inrU9C4PqU-vaJoUVjWexjc", "7isHbo97jZWPlWRUrQA0DGn8Lt8c8ldq98hG8RmxVrk", "AamKarfqyA43tuu8nv_VAscP_gGrOT15LC3uYaCzjNw", "U1sgOjjQTmb8gaa3tjzPcc8Ab82uJn3ObQVJJHon1Q4", "6FQFVXc37_7y5OHYfoNLl8g-Xug2jqYcCmEH48ZARlc", "7HIpnXi5dKo75lbHkplURQMhgjCgRbcp5cGFIUYuLNw", "85_pWcJ5ke9fiy-qqqckkIpZ_njK92kTjcFWWbGr_zk" ] Figure 24: Derived payload keys (base64url-encoded) A MAC is generated for each payload using the corresponding derived payload key. This results in the following set of MAC values: [ "anrPRjCx1q2XSRYgU-On7qeB_8zr-t6P5AQk3ubOsFY", "S79JrwfnxXXIosjZSLotXmDc29k4mQ6bJ_GsThmcSMQ", "ioy-D2skjQa8P70OYnDlcy9AOw3HmAZDtjIdfnJD-VQ", "2BO9zL8ISB_6eEn0agZ-pQR_xIQcZ9mrMN1zUppOLWI", "eEfyfQmtGFZSRNk0BdN-GPWam7sVD2CLMqz8GxNBNQ8", "80sdl_L8HYHCsNh4A_YxVpL8t5mEXWBgyzYQI_Vfj9w", "rsuALZxSYGcxJDgvxMG-0kUppVc8vDdWoTcu7VlMJ-U" ] Figure 25: Payload MAC values (base64url-encoded) The issuer protected header MAC and the payload MAC octet strings are concatenated into a single value known as the combined MAC representation. This representation is signed with the issuer's private key. The proof consists of two octet string values: the signature over the combined MAC representation, and the shared secret. [ "cLGnQhMW7E329q6Tjs1xtVZJUhAuBbH8CDYVvnSl5JyNLG3WxMmv85Y8FdRQ7BMhx3 Tn_1wWDOI-nZEvpJJgMg", "0jXHLZ-vz6M4-ss4kgMC5kX3Pk8u8vIAAQ-qHMC1NmU" ] Figure 26: Issued Proof (base64url-encoded) The final issued JWP in JSON serialization is: { "issuer": "eyJhbGciOiJNQUMtSDI1NiIsInR5cCI6IkpQVCIsImlzcyI6Imh0dHBz Oi8vaXNzdWVyLmV4YW1wbGUiLCJjbGFpbXMiOlsiaWF0IiwiZXhwIiwiZmFtaWx5X25hb WUiLCJnaXZlbl9uYW1lIiwiZW1haWwiLCJhZGRyZXNzIiwiYWdlX292ZXJfMjEiXSwicH Jlc2VudGF0aW9uX2tleSI6eyJrdHkiOiJFQyIsImNydiI6IlAtMjU2IiwidXNlIjoic2l nbiIsIngiOiJWdGRJcExxTWRldFRCbXBSME1xNWFQR3VDUWR3X3pKbVpCYUtkNzdlNmRV IiwieSI6IlRxRVFJcXdnaXpNcU84TzVaVmViSWJNXzNjZ3M4TTJZRFBid2JLVENvS0kif X0", "payloads": [ "MTcxNDUyMTYwMA", "MTcxNzE5OTk5OQ", "IkRvZSI", "IkpheSI", "ImpheWRvZUBleGFtcGxlLm9yZyI", "eyJmb3JtYXR0ZWQiOiIxMjM0IE1haW4gU3QuXG5Bbnl0b3duLCBDQSAxMjM0NVxu VVNBIiwic3RyZWV0X2FkZHJlc3MiOiIxMjM0IE1haW4gU3QuIiwibG9jYWxpdHkiOiJBb nl0b3duIiwicmVnaW9uIjoiQ0EiLCJwb3N0YWxfY29kZSI6MTIzNDUsImNvdW50cnkiOi JVU0EifQ", "dHJ1ZQ" ], "proof": [ "cLGnQhMW7E329q6Tjs1xtVZJUhAuBbH8CDYVvnSl5JyNLG3WxMmv85Y8FdRQ7BMh x3Tn_1wWDOI-nZEvpJJgMg", "0jXHLZ-vz6M4-ss4kgMC5kX3Pk8u8vIAAQ-qHMC1NmU" ] } Figure 27: Issued JWP (in JSON serialization) The same JWP in compact serialization: eyJhbGciOiJNQUMtSDI1NiIsInR5cCI6IkpQVCIsImlzcyI6Imh0dHBzOi8vaXNzdWVyL mV4YW1wbGUiLCJjbGFpbXMiOlsiaWF0IiwiZXhwIiwiZmFtaWx5X25hbWUiLCJnaXZlbl 9uYW1lIiwiZW1haWwiLCJhZGRyZXNzIiwiYWdlX292ZXJfMjEiXSwicHJlc2VudGF0aW9 uX2tleSI6eyJrdHkiOiJFQyIsImNydiI6IlAtMjU2IiwidXNlIjoic2lnbiIsIngiOiJW dGRJcExxTWRldFRCbXBSME1xNWFQR3VDUWR3X3pKbVpCYUtkNzdlNmRVIiwieSI6IlRxR VFJcXdnaXpNcU84TzVaVmViSWJNXzNjZ3M4TTJZRFBid2JLVENvS0kifX0.MTcxNDUyMT YwMA~MTcxNzE5OTk5OQ~IkRvZSI~IkpheSI~ImpheWRvZUBleGFtcGxlLm9yZyI~eyJmb 3JtYXR0ZWQiOiIxMjM0IE1haW4gU3QuXG5Bbnl0b3duLCBDQSAxMjM0NVxuVVNBIiwic3 RyZWV0X2FkZHJlc3MiOiIxMjM0IE1haW4gU3QuIiwibG9jYWxpdHkiOiJBbnl0b3duIiw icmVnaW9uIjoiQ0EiLCJwb3N0YWxfY29kZSI6MTIzNDUsImNvdW50cnkiOiJVU0EifQ~d HJ1ZQ.cLGnQhMW7E329q6Tjs1xtVZJUhAuBbH8CDYVvnSl5JyNLG3WxMmv85Y8FdRQ7BM hx3Tn_1wWDOI-nZEvpJJgMg~0jXHLZ-vz6M4-ss4kgMC5kX3Pk8u8vIAAQ-qHMC1NmU Figure 28: Issued JWP (in compact serialization) Next, we show the presentation of the JWP with selective disclosure. For presentation with the following presentation protected header: { "alg": "MAC-H256", "aud": "https://recipient.example.com", "nonce": "KZPGrOOm3m3gotj8s2fChQsoS-_YcIbo_WCQSuPYgzs" } Figure 29: Presentation Protected Header The holder will take the issuer proof (including shared secret) and derive the same individual payload MAC values (above). In this case, the holder has decided not to disclose the last three claims provided by the issuer (corresponding to email, address, and age_over_21) For the disclosed payloads, the holder will provide the corresponding derived key. For the non-disclosed payloads, the holder will provide the corresponding MAC value. The final presented proof value is an array of octet strings. The contents are presentation header signature, followed by the issuer signature, then the value disclosed by the holder for each payload. This results in the following proof: [ "u21PvrVtoVVe-qjBeR9Se5PABb8f5tA01pLi1Wahi5myVkPwE-7STO-9mHcMx5mTN9 CzCcVd47XFk9DJJaSy-Q", "cLGnQhMW7E329q6Tjs1xtVZJUhAuBbH8CDYVvnSl5JyNLG3WxMmv85Y8FdRQ7BMhx3 Tn_1wWDOI-nZEvpJJgMg", "bm8tJeEw895F8kFtaja_inrU9C4PqU-vaJoUVjWexjc", "7isHbo97jZWPlWRUrQA0DGn8Lt8c8ldq98hG8RmxVrk", "AamKarfqyA43tuu8nv_VAscP_gGrOT15LC3uYaCzjNw", "U1sgOjjQTmb8gaa3tjzPcc8Ab82uJn3ObQVJJHon1Q4", "eEfyfQmtGFZSRNk0BdN-GPWam7sVD2CLMqz8GxNBNQ8", "80sdl_L8HYHCsNh4A_YxVpL8t5mEXWBgyzYQI_Vfj9w", "rsuALZxSYGcxJDgvxMG-0kUppVc8vDdWoTcu7VlMJ-U" ] Figure 30: Presentation proof (base64url-encoded) The final presented JWP in JSON serialization is: { "presentation": "eyJhbGciOiJNQUMtSDI1NiIsImF1ZCI6Imh0dHBzOi8vcmVjaX BpZW50LmV4YW1wbGUuY29tIiwibm9uY2UiOiJLWlBHck9PbTNtM2dvdGo4czJmQ2hRc29 TLV9ZY0lib19XQ1FTdVBZZ3pzIn0", "issuer": "eyJhbGciOiJNQUMtSDI1NiIsInR5cCI6IkpQVCIsImlzcyI6Imh0dHBz Oi8vaXNzdWVyLmV4YW1wbGUiLCJjbGFpbXMiOlsiaWF0IiwiZXhwIiwiZmFtaWx5X25hb WUiLCJnaXZlbl9uYW1lIiwiZW1haWwiLCJhZGRyZXNzIiwiYWdlX292ZXJfMjEiXSwicH Jlc2VudGF0aW9uX2tleSI6eyJrdHkiOiJFQyIsImNydiI6IlAtMjU2IiwidXNlIjoic2l nbiIsIngiOiJWdGRJcExxTWRldFRCbXBSME1xNWFQR3VDUWR3X3pKbVpCYUtkNzdlNmRV IiwieSI6IlRxRVFJcXdnaXpNcU84TzVaVmViSWJNXzNjZ3M4TTJZRFBid2JLVENvS0kif X0", "payloads": [ "MTcxNDUyMTYwMA", "MTcxNzE5OTk5OQ", "IkRvZSI", "IkpheSI", null, null, null ], "proof": [ "u21PvrVtoVVe-qjBeR9Se5PABb8f5tA01pLi1Wahi5myVkPwE-7STO-9mHcMx5mT N9CzCcVd47XFk9DJJaSy-Q", "cLGnQhMW7E329q6Tjs1xtVZJUhAuBbH8CDYVvnSl5JyNLG3WxMmv85Y8FdRQ7BMh x3Tn_1wWDOI-nZEvpJJgMg", "bm8tJeEw895F8kFtaja_inrU9C4PqU-vaJoUVjWexjc", "7isHbo97jZWPlWRUrQA0DGn8Lt8c8ldq98hG8RmxVrk", "AamKarfqyA43tuu8nv_VAscP_gGrOT15LC3uYaCzjNw", "U1sgOjjQTmb8gaa3tjzPcc8Ab82uJn3ObQVJJHon1Q4", "eEfyfQmtGFZSRNk0BdN-GPWam7sVD2CLMqz8GxNBNQ8", "80sdl_L8HYHCsNh4A_YxVpL8t5mEXWBgyzYQI_Vfj9w", "rsuALZxSYGcxJDgvxMG-0kUppVc8vDdWoTcu7VlMJ-U" ] } Figure 31: Presented JWP (in JSON serialization) The same JWP in compact serialization: eyJhbGciOiJNQUMtSDI1NiIsImF1ZCI6Imh0dHBzOi8vcmVjaXBpZW50LmV4YW1wbGUuY 29tIiwibm9uY2UiOiJLWlBHck9PbTNtM2dvdGo4czJmQ2hRc29TLV9ZY0lib19XQ1FTdV BZZ3pzIn0.eyJhbGciOiJNQUMtSDI1NiIsInR5cCI6IkpQVCIsImlzcyI6Imh0dHBzOi8 vaXNzdWVyLmV4YW1wbGUiLCJjbGFpbXMiOlsiaWF0IiwiZXhwIiwiZmFtaWx5X25hbWUi LCJnaXZlbl9uYW1lIiwiZW1haWwiLCJhZGRyZXNzIiwiYWdlX292ZXJfMjEiXSwicHJlc 2VudGF0aW9uX2tleSI6eyJrdHkiOiJFQyIsImNydiI6IlAtMjU2IiwidXNlIjoic2lnbi IsIngiOiJWdGRJcExxTWRldFRCbXBSME1xNWFQR3VDUWR3X3pKbVpCYUtkNzdlNmRVIiw ieSI6IlRxRVFJcXdnaXpNcU84TzVaVmViSWJNXzNjZ3M4TTJZRFBid2JLVENvS0kifX0. MTcxNDUyMTYwMA~MTcxNzE5OTk5OQ~IkRvZSI~IkpheSI~~~.u21PvrVtoVVe-qjBeR9S e5PABb8f5tA01pLi1Wahi5myVkPwE-7STO-9mHcMx5mTN9CzCcVd47XFk9DJJaSy-Q~cL GnQhMW7E329q6Tjs1xtVZJUhAuBbH8CDYVvnSl5JyNLG3WxMmv85Y8FdRQ7BMhx3Tn_1w WDOI-nZEvpJJgMg~bm8tJeEw895F8kFtaja_inrU9C4PqU-vaJoUVjWexjc~7isHbo97j ZWPlWRUrQA0DGn8Lt8c8ldq98hG8RmxVrk~AamKarfqyA43tuu8nv_VAscP_gGrOT15LC 3uYaCzjNw~U1sgOjjQTmb8gaa3tjzPcc8Ab82uJn3ObQVJJHon1Q4~eEfyfQmtGFZSRNk 0BdN-GPWam7sVD2CLMqz8GxNBNQ8~80sdl_L8HYHCsNh4A_YxVpL8t5mEXWBgyzYQI_Vf j9w~rsuALZxSYGcxJDgvxMG-0kUppVc8vDdWoTcu7VlMJ-U Figure 32: Presented JWP (in compact serialization) Appendix B. Acknowledgements This work was incubated in the DIF Applied Cryptography Working Group (https://identity.foundation/working-groups/crypto.html). We would like to thank Alberto Solavagione for his valuable contributions to this specification. The BBS examples were generated using the library at https://github.com/mattrglobal/pairing_crypto (https://github.com/mattrglobal/pairing_crypto) . Appendix C. Document History [[ To be removed from the final specification ]] -latest * Defer BBS key definition to [I-D.ietf-cose-bls-key-representations] * Modify example generation to use proof_key and presentation_key names * Change proof_jwk to proof_key and presentation_jwk to presentation_key to better represent that the key may be JSON or CBOR-formatted. * Moved the registry for proof_key and presentation_key to JWP where they are defined. Consolidated usage, purpose and requirements from algorith musage under these definitions. -06 * Update reference to new repository home * Fixed #77: Removed vestigial use of presentation_header. * Correct pjwk to presentation_jwk -05 * Update of appendix describing MAC-H256 to now also be generated by the build system from a common set of code and templates. * Update single use algorithm to use an array of octet values rather than requiring splitting an octet buffer into parts during generation of a presentation and during verification. * Update BBS algorithm description and examples to clarify the proof is an array with a single octet string. * Update MAC algorithm to use an array of octet values for the proof, rather than requiring splitting an octet buffer into parts. * Add new section on the Combined MAC Representation to clarify operations are serving to recreate this octet string value. * Correct reference to the latest BBS draft. * SU and MAC families now use raw JWA rather than JWS and synthesized headers * Change algorithms to not use base64url-encoding internally. Algorithms are meant to operate on octets, while base64url- encoding is used to represent those octets in JSON and compact serializations. -04 * Refactoring figures and examples to be built from a common set across all three documents * Move single-use example appendix from JWP to JPA * Change algorithm from BBS-DRAFT-5 to BBS, and from BBS-PROOF- DRAFT-5 to BBS-PROOF * Update BBS ciphersuite ID to BBS_BLS12381G1_XMD:SHA-256_SSWU_RO_ * Update to draft 5 BLS key representations -03 * Improvements resulting from a full proofreading. * Populated IANA Considerations section. * Updated to use BBS draft -05. * Updated examples. -02 * Add new BBS-DRAFT-3 and BBS-PROOF-DRAFT-3 algorithms based on draft-irtf-cfrg-bbs-signatures-03. * Remove prior BBS-X algorithm based on a particular implementation of earlier drafts. -01 * Correct cross-references within group * Describe issuer_header and presentation_header * Update BBS references to CFRG drafts * Rework reference to HMAC ( RFC2104 ) * Remove ZKSnark placeholder -00 * Created initial working group draft based on draft-jmiller-jose- json-proof-algorithms-01 Authors' Addresses Jeremie Miller Ping Identity Email: jmiller@pingidentity.com Michael B. Jones Self-Issued Consulting Email: michael_b_jones@hotmail.com URI: https://self-issued.info/ David Waite Ping Identity Email: dwaite+jwp@pingidentity.com