jose M. Jones Internet-Draft Self-Issued Consulting Intended status: Standards Track D. Waite Expires: 7 January 2026 J. Miller Ping Identity 6 July 2025 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 7 January 2026. Copyright Notice Copyright (c) 2025 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 #{presentation-protected-header} 6.1.9. Presentation 6.1.10. Verification of Presentation 6.1.11. JPA Registration 6.2. Presentation Internal Representation 6.3. BBS 6.3.1. JPA Algorithms 6.3.2. Key Format 6.3.3. Issuance 6.3.4. Issuance Proof Verification 6.3.5. Presentation 6.3.6. Presentation Verification 6.4. Message Authentication Code 6.4.1. Holder Setup 6.4.2. Issuer Setup 6.4.3. Combined MAC Representation 6.4.4. Issuer Protected Header 6.4.5. Issuer Proof 6.4.6. Presentation Protected Header 6.4.7. Presentation Proof 6.4.8. Verification of the Presentation Proof 6.4.9. 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. MAC-H256 Algorithm 8.1.2.6. MAC-H384 Algorithm 8.1.2.7. MAC-H512 Algorithm 8.1.2.8. MAC-K25519 Algorithm 8.1.2.9. MAC-K448 Algorithm 8.1.2.10. MAC-H256K Algorithm 9. References 9.1. Normative References 9.2. Informative References Appendix A. Example JWPs A.1. Example JSON-Serialized Single-Use JWP A.2. Example CBOR-Serialized Single-Use CPT A.3. Example BBS JWP A.4. 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 uses multiple signing keys to protect the protected header as well as individual payloads of an Issued JWP. The issuer uses a stable public key to sign each protected header, and a per-JWP ephemeral key (conveyed within the protected header) to protect the individual payloads. These signatures are all created using the same Asymmetric Algorithm, with the JOSE and COSE name/ label of this algorithm being part of registration for a fully- specified Single Use algorithm identifier. The issuer protected header also conveys a holder presentation key, an ephemeral asymmetric key meant to only be used for presenting a single JWP. The fully-specified algorithm the holder must use for presentations is also included. This algorithm MAY be different from the algorithm used by the issuer. The chosen algorithms MUST be an asymmetric signing algorithms, so that each signature can be verified without sharing any private values between the parties. 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. The issuer MUST deterine an appropriate holder presentation algorithm corresponding to the presentation key. If the holder and verifier cannot be assumed to know this algorithm is the appropriate choice for a given presentation key, this value MUST be conveyed in the hpa issuer protected header. 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 via the Proof Key header parameter. The Holder's Presentation Key MUST be included via the Presentation Key header parameter. The Holder's Presentation Algorithm MUST be included via the Holder Presentation Algorithm header parameter, unless there is another way for the holder and verifier to unambiguously determine the appropriate algorithm to use. The Issuer Protected Header is signed using the appropriate internal signing algorithm for the given fully-specified single use algorithm, using 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 #{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. The presentation protected header MUST contain the same Algorithm protected header as the issuer protected header. The Holder Presentation Algorithm protected header MUST NOT be included. 6.1.9. Presentation The holder derives a new proof as part of presentation. The holder will also use these components to generate a presentation internal representation (#presention-internal-representation). The number of components depends on the number of payloads which are being disclosed in the presented JWP. The first proof component will be the signature over the issuer protected header made by the issuer's Stable Key. For each payload which is to be disclosed, the corresponding payload signature (from the issued JWP) is included as a subsequent proof component. If the payload is being omitted, the corresponding payload signature is omitted from the proof components. The holder protected header, issuer protected header, payload slots (distinguishing which are being disclosed) and these proof components are inputs to determine the presentation internal representation. The holder's signature over the presentation internal representation (using the holder's private key and the holder presentation algorithm) is then included as one additional proof component in the final presentation. For example, if only the second and fifth of five payloads are being disclosed, then the proof at this stage will consist of three values: 1. The issuer's signature over the issuer protected header 2. The payload signature corresponding to the second payload 3. The payload signature corresponding to the fifth payload. The presentation internal representation would be calculated with these three proof components, while the final presentation would have an additional 4th component containing the signature using the holder's private key. 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 of Presentation Verification is performed using the following steps. 1. Check the number of proof components is appropriate for the number of disclosed payloads. There MUST be two more proof components than disclosed payloads. 2. Verify the first proof component is a valid signature over issuer protected header octets, using the issuer's stable key. 3. Extract the presentation key and holder presentation algorithm (if present) from the issuer protected header. 4. Omitting the final payload component, calculate the presentation internal representation (#presentation-internal-representation). 5. Verify the final proof component is a valid signature over the presentation internal binary form, using the holder's presentation key and the extracted (or otherwise determined) holder presentation algorithm. 6. For each remaining proof component, verify they form a valid signature over each disclosed payload in sequence, using the issuer's ephemeral key. 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. Presentation Internal Representation Some algorithms (such as Single use and MAC) use a holder key to provide integrity over the presentation. For these algorithms, an internal binary form of the presentation must be generated both for signing by the holder, and for verification by the verifier. Other algorithms MAY use this same form for consistency. The instructions for creating this binary representation will also create well-formed CBOR, although this data is not meant to be shared outside the implementing algorithm. Instead, it focuses on simplicity of generation by the holder and verifier implementations. Although CBOR has multiple representations of the same underlying information, this same octet string MUST be generated by an implementation. When a length or count is added by the steps below, it is added as its 8 byte, network-ordered representation. For example, the length of a 1,234 byte payload would have a length representation of 0x00 00 00 00 00 00 04 D2. The binary representation is created by appending data into a single octet string in the following order: 1. 0x84 5A 2. The length and octets of the presentation protected header 3. 0x5A 4. The length and octets of the issuer protected header 5. 0x9A 6. The number of payload slots in the issued message 7. For each payload representation: * If the payload is being ommitted, the value 0xF6 * Otherwise: 1. 0x5A 2. The length and octets of the payload 8. 0x9A 9. The number of proof components as specified by the algorithm 10. For each proof component, append: 1. 0x5A 2. The length and octets of the proof component 6.3. 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. 6.3.1. JPA Algorithms The BBS algorithm corresponds to a ciphersuite identifier of BBS_BLS12381G1_XMD:SHA-256_SSWU_RO_. 6.3.2. 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. 6.3.3. 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. 6.3.4. 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. 6.3.5. 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 CBOR serialization and a zero-length string in compact serialization. 6.3.6. 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. 6.4. Message Authentication Code The Message Authentication Code (MAC) JPA uses a MAC to both generate emphemeral secrets and to authenticate payloads, along with an asymmetric signature to provide integrity to the issued JWP. The holder can manipulate which payloads are disclosed from the issued JWP, and uses the holder Presentation Key to create a presentation. The signature created from the Holder Presentation Key MAY use a different algorithm than the Issuer used to sign the issued form. 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. 6.4.1. 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. The issuer MUST deterine an appropriate holder presentation algorithm corresponding to the presentation key. If the holder and verifier cannot be assumed to know this algorithm is the appropriate choice for a given presentation key, this value MUST be conveyed in the Holder Protected algoirhtm header parameter. 6.4.2. 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. 6.4.3. 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 steps below describe a sequential concatenation of binary values to generate the Combined MAC Representation. The instructions for generating this octet string will also generate well-formed CBOR, although this data is not meant to be shared outside the implementing algorithm. Instead, it focuses on simplicity of generation by the issuer, holder and verifier implementations. Although CBOR has multiple representations of the same underlying information, this same octet string MUST be generated by an implementation. When a length or count is added by steps in this section, it is added as its 8 byte, network-ordered representation. For example, the length of a 1,234 byte payload would have a length representation of 0x00 00 00 00 00 00 04 D2. The holder will a unique key per payload value using a MAC, with the Shared Secret as the key and a generated binary value. This binary value is constructed by appending data into a single octet string: 1. 0x82 67 70 61 79 6C 6F 61 64 48 1A 2. The zero indexed count of the payload slot The holder will also compute a corresponding MAC of each payload. This MAC uses the unique key above and the payload octet string as the value. When verifying a presentation, the shared secret will be unavailable so the unique key cannot be calculated. The payload octet string may also be omitted in the presentation. The following instructions describe how to get the corresponding MAC of each payload: * If the payload is disclosed, the corresponding proof component (as described in the (Presentation Proof section)[#mac-presentation- proof] will contain the generated unique key. The payload MAC will be calculated using this key and the payload octets as the value. * If the payload is not disclosed, the corresponding proof component will be the payload MAC. The binary representation is created by appending data into a single octet string in the following order: 1. 0x82 5A 2. The length and octets of the issuer protected header 3. 0x9A 4. The number of payload slots in the issued JWP 5. For each payload representation: 1. 0x5A 2. The length and value of the per payload MAC 6.4.4. Issuer Protected Header The Holder's Presentation Key MUST be included via the Presentation Key header parameter. The Holder's Presentation Algorithm MUST be included via the Holder Presentation Algorithm header parameter, unless there is another way for the holder and verifier to unambiguously determine the appropriate algorithm to use. 6.4.5. 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 combined MAC representation using its stable public key, and the internal signing algorithm for the given fully-specified MAC algorithm variant. The second octet string is the Shared Secret used to generate the per-payload keys for the combined representation. 6.4.6. Presentation Protected Header See the Presentation Protected Header (#presentation-protected- header) section given for Single Use algorithms. 6.4.7. Presentation Proof The presentation proof is made of multiple components. The first proof component is the issuer signature over the Combined MAC Representation, which is provided as the first proof component from the issued form. There will now be one proof component per payload slot in the issued JWP. These are used by the verifier to reconstruct the combined MAC representation without access to the Shared Secret. The proof components are calculated per the instructions used to generate the Combined MAC Representation (#combined-mac-representation) If a payload is disclosed, the corresponding proof component will be the unique key. If a payload is not disclosed, the corresponding proof component will be the payload's MAC (using the unique key.) The holder protected header, issuer protected header, payload slots (distinguishing which are being disclosed) and above proof components are inputs to determine the presentation internal representation (#presentation-internal-representation). The holder's signature over the presentation internal representation (using the holder's private key and the holder presentation algorithm) is then included as one additional proof component in the final presentation. The presented form should have two more proof components than payload slots in the issued JWP. Note that the second component of the issued JWP is a shared secret for use by the holder to generate the unique keys used in the Combined MAC Representation. This MUST NOT be included in the presentation. 6.4.8. Verification of the Presentation Proof Verification is performed using the following steps. 1. Check the number of proof components is appropriate for the number of disclosed payloads. There MUST be two more proof components than disclosed payloads. 2. Using the fully-specified MAC algorithm in use, use the issuer protected header, disclosed payloads, and the proof components corresopnding to the payloads to regenerate the Combined MAC Representation. 3. Verify the first proof component is a valid signature over the issuer protected header octets, using the issuer's stable key. 4. Extract the presentation key and holder presentation algorithm (if present) from the issuer protected header. 5. Omitting the final payload component, calculate the presentation internal representation (#presentation-internal-representation). 6. Verify the final proof component is a valid signature over the presentation internal binary form, using the holder's presentation key and the extracted (or otherwise determined) holder presentation algorithm. 6.4.9. 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, Presented * JWP Implementation Requirements: Required * Change Controller: IETF * Specification Document(s): Section 6.3.1 of this specification * Algorithm Analysis Documents(s): n/a 8.1.2.5. MAC-H256 Algorithm * Algorithm Name: MAC-H256 * Algorithm JSON Label: MAC-H256 * Algorithm CBOR Label: 5 * 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 6.4.9 of this specification * Algorithm Analysis Documents(s): n/a 8.1.2.6. MAC-H384 Algorithm * Algorithm Name: MAC-H384 * Algorithm JSON Label: MAC-H384 * Algorithm CBOR Label: 6 * 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 6.4.9 of this specification * Algorithm Analysis Documents(s): n/a 8.1.2.7. MAC-H512 Algorithm * Algorithm Name: MAC-H512 * Algorithm JSON Label: MAC-H512 * Algorithm CBOR Label: 7 * 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 6.4.9 of this specification * Algorithm Analysis Documents(s): n/a 8.1.2.8. MAC-K25519 Algorithm * Algorithm Name: MAC-K25519 * Algorithm JSON Label: MAC-K25519 * Algorithm CBOR Label: 8 * 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 6.4.9 of this specification * Algorithm Analysis Documents(s): n/a 8.1.2.9. MAC-K448 Algorithm * Algorithm Name: MAC-K448 * Algorithm JSON Label: MAC-K448 * Algorithm CBOR Label: 9 * 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 6.4.9 of this specification * Algorithm Analysis Documents(s): n/a 8.1.2.10. MAC-H256K Algorithm * Algorithm Name: MAC-H256K * Algorithm JSON Label: MAC-H256K * Algorithm CBOR Label: 10 * 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 6.4.9 of this specification * Algorithm Analysis Documents(s): n/a 9. References 9.1. Normative References [I-D.ietf-jose-json-web-proof] Waite, D., Jones, M. B., and J. Miller, "JSON Web Proof", Work in Progress, Internet-Draft, draft-ietf-jose-json- web-proof-latest, . [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-08, 3 March 2025, . [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC7515] Jones, M., Bradley, J., and N. Sakimura, "JSON Web Signature (JWS)", RFC 7515, DOI 10.17487/RFC7515, 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, . 9.2. Informative References [I-D.ietf-cbor-edn-literals] Bormann, C., "CBOR Extended Diagnostic Notation (EDN)", Work in Progress, Internet-Draft, draft-ietf-cbor-edn- literals-17, 12 May 2025, . [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-06, 18 January 2025, . [I-D.maldant-spice-oidc-cwt] Maldant, B., "OpenID Connect standard claims registration for CBOR Web Tokens", Work in Progress, Internet-Draft, draft-maldant-spice-oidc-cwt-02, 17 March 2025, . [RFC2104] Krawczyk, H., Bellare, M., and R. Canetti, "HMAC: Keyed- Hashing for Message Authentication", RFC 2104, DOI 10.17487/RFC2104, February 1997, . [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an IANA Considerations Section in RFCs", RFC 5226, DOI 10.17487/RFC5226, May 2008, . [RFC7518] Jones, M., "JSON Web Algorithms (JWA)", RFC 7518, DOI 10.17487/RFC7518, May 2015, . [VC-DATA-MODEL-2.0] Sporny, M., Jr, T. T., Herman, I., Cohen, G., and M. B. Jones, "Verifiable Credentials Data Model v2.0", 15 May 2025, . 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 JSON-Serialized 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": "SYnFf5rvTjTXqn17cpaJ6-WtBQrdp27h8PXskTBKtXY", "y": "aXb61CiSXsQb012hun68cUczn4TVHbnqrvdFLoUCCCk", "d": "m47JVI153rBlUii22gy_0Xn8JWidGhQZzJEiR_hhEgg" } Figure 1: Issuer Private Key (ES256 in JWK) This is the ephemeral private key used in this example in the JWK format: { "kty": "EC", "crv": "P-256", "x": "NKRNYBUMP5Vi-Q_XDi3-5C8zHAMcu_pPmr8GSdkUUlg", "y": "thb-w8mhaS2_fjvSp6FoHPePN9sFJWHGAxRh_lUWo0w", "d": "ZGsOG1dd-C3-gq0pKTuwXWC2i68qD0ZiN8jaQfusVU4" } Figure 2: Issuer Ephemeral Private Key (ES256 in JWK) This is the Holder's presentation private key used in this example in the JWK format: { "kty": "EC", "crv": "P-256", "x": "HC9UE7VySnU4KtlDGooOAuNsOEl5Jn12U_chGuaRcvs", "y": "qD9GleC38PPrQlJB4P7QHI7B7e3LjzcmmyW_RV5LVRc", "d": "kppFYxR3QmhzPU6SO3mYiVFRiAX1rffnLf6gNyMPbrE" } Figure 3: Holder Presentation Private Key (ES256 in JWK) 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": "NKRNYBUMP5Vi-Q_XDi3-5C8zHAMcu_pPmr8GSdkUUlg", "y": "thb-w8mhaS2_fjvSp6FoHPePN9sFJWHGAxRh_lUWo0w" }, "presentation_key": { "kty": "EC", "crv": "P-256", "x": "HC9UE7VySnU4KtlDGooOAuNsOEl5Jn12U_chGuaRcvs", "y": "qD9GleC38PPrQlJB4P7QHI7B7e3LjzcmmyW_RV5LVRc" } } Figure 4: Issuer Protected header (SU-ES256, JSON) eyJhbGciOiJTVS1FUzI1NiIsInR5cCI6IkpQVCIsImlzcyI6Imh0dHBzOi8vaXNzdWVyL mV4YW1wbGUiLCJjbGFpbXMiOlsiaWF0IiwiZXhwIiwiZmFtaWx5X25hbWUiLCJnaXZlbl 9uYW1lIiwiZW1haWwiLCJhZGRyZXNzIiwiYWdlX292ZXJfMjEiXSwicHJvb2Zfa2V5Ijp 7Imt0eSI6IkVDIiwiY3J2IjoiUC0yNTYiLCJ4IjoiTktSTllCVU1QNVZpLVFfWERpMy01 Qzh6SEFNY3VfcFBtcjhHU2RrVVVsZyIsInkiOiJ0aGItdzhtaGFTMl9manZTcDZGb0hQZ VBOOXNGSldIR0F4UmhfbFVXbzB3In0sInByZXNlbnRhdGlvbl9rZXkiOnsia3R5IjoiRU MiLCJjcnYiOiJQLTI1NiIsIngiOiJIQzlVRTdWeVNuVTRLdGxER29vT0F1TnNPRWw1Sm4 xMlVfY2hHdWFSY3ZzIiwieSI6InFEOUdsZUMzOFBQclFsSkI0UDdRSEk3QjdlM0xqemNt bXlXX1JWNUxWUmMifX0 Figure 5: Encoded Issuer Protected Header (SU-ES256, JSON, 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. [ 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 6: Issuer payloads (JSON, as array) The compact serialization of the same JPT is: eyJhbGciOiJTVS1FUzI1NiIsInR5cCI6IkpQVCIsImlzcyI6Imh0dHBzOi8vaXNzdWVyL mV4YW1wbGUiLCJjbGFpbXMiOlsiaWF0IiwiZXhwIiwiZmFtaWx5X25hbWUiLCJnaXZlbl 9uYW1lIiwiZW1haWwiLCJhZGRyZXNzIiwiYWdlX292ZXJfMjEiXSwicHJvb2Zfa2V5Ijp 7Imt0eSI6IkVDIiwiY3J2IjoiUC0yNTYiLCJ4IjoiTktSTllCVU1QNVZpLVFfWERpMy01 Qzh6SEFNY3VfcFBtcjhHU2RrVVVsZyIsInkiOiJ0aGItdzhtaGFTMl9manZTcDZGb0hQZ VBOOXNGSldIR0F4UmhfbFVXbzB3In0sInByZXNlbnRhdGlvbl9rZXkiOnsia3R5IjoiRU MiLCJjcnYiOiJQLTI1NiIsIngiOiJIQzlVRTdWeVNuVTRLdGxER29vT0F1TnNPRWw1Sm4 xMlVfY2hHdWFSY3ZzIiwieSI6InFEOUdsZUMzOFBQclFsSkI0UDdRSEk3QjdlM0xqemNt bXlXX1JWNUxWUmMifX0.MTcxNDUyMTYwMA~MTcxNzE5OTk5OQ~IkRvZSI~IkpheSI~Imp heWRvZUBleGFtcGxlLm9yZyI~eyJmb3JtYXR0ZWQiOiIxMjM0IE1haW4gU3QuXG5Bbnl0 b3duLCBDQSAxMjM0NVxuVVNBIiwic3RyZWV0X2FkZHJlc3MiOiIxMjM0IE1haW4gU3QuI iwibG9jYWxpdHkiOiJBbnl0b3duIiwicmVnaW9uIjoiQ0EiLCJwb3N0YWxfY29kZSI6MT IzNDUsImNvdW50cnkiOiJVU0EifQ~dHJ1ZQ.kVq10Cvsta8kNQphGQtmmDbdATtADBT2d hvkWKydge0TxdaF32rffEP_fkFYr5IFza5CUXUN0A9RBHeP1vg5vQ~pwy1wFWM3VDihxd PTrWFWPiGIXFeKaSu-xmJMixZ2pHGlj2pKIxTq97Ad9-SZDc8kc9S_OU8fCchIMcOY_0y Ow~IdA4jo-Tm5Fo7j_0PNQdmn6FQxH5BbvmTtvJTCWmxYnf4xM2UII8N2Um_WWLGjJm_r C665HmvJuPmNFif_JywA~h7igZFgMiLCBqkISeKXO-K57WhznZuaNFpmnOPtYcIsa8twl ZsRNC5sx_HuMe72UgfVUiEryzW89cmUCokb8TQ~IQneMikxkNZ_VoHDZzpZOE4RKhI_0E AGQ1QhmrJnPd66iQXO1HSBADKT9xEkU8OTqd_PL23khNT-EkGQ72-Tpw~sHItG7FuxuT2 cqlMmW30H-3jMMFE8sHpwQCniOZqvxT-XLBJ8aCRXW70FRpkLhdzyZ9OQM97L1kgalrL3 r7-Kw~hkqbgsHjea3ncNf-Uj6c2OYhksv-PV25dx9ppt7dXaXNwGPyVcsEPDIEjh1fiAi 3RP2__orQzEe07RwCbmxG8Q~98ji_ikFRBddXlc_LCH9DP6P6q3fW2oMDSAzat0jprKbz K50AgHulP4eBcHoUMFUhn6GPBPscmTa--aX5mgYzg Figure 7: Issued JWP (SU-ES256, JSON, Compact Serialization) 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": "kSeWr0PiPkAQ1qzhSx3KVMnZbC7UD1lIItBUQS88zvg" } Figure 8: Presentation Header (SU-ES256, JSON) eyJhbGciOiJTVS1FUzI1NiIsImF1ZCI6Imh0dHBzOi8vcmVjaXBpZW50LmV4YW1wbGUuY 29tIiwibm9uY2UiOiJrU2VXcjBQaVBrQVExcXpoU3gzS1ZNblpiQzdVRDFsSUl0QlVRUz g4enZnIn0 Figure 9: Presentation Header (SU-ES256, JSON, Base64url-Encoded) When signed with the holder's presentation key, the resulting signature are: SSbKbyzKEfnq6eqW-fR6QsHQrS6HOAu2is7_-SBUcaxLDoIFvn0Cu4HauUm09ymBdX5xI HU08gq2_EFhcYKAPw | Figure: Holder Proof-of-Possession (SU-ES256, JSON) Then by applying selective disclosure of only the given name and age claims (family name and email hidden), we get the following presented JPT in compact serialization: eyJhbGciOiJTVS1FUzI1NiIsImF1ZCI6Imh0dHBzOi8vcmVjaXBpZW50LmV4YW1wbGUuY 29tIiwibm9uY2UiOiJrU2VXcjBQaVBrQVExcXpoU3gzS1ZNblpiQzdVRDFsSUl0QlVRUz g4enZnIn0.eyJhbGciOiJTVS1FUzI1NiIsInR5cCI6IkpQVCIsImlzcyI6Imh0dHBzOi8 vaXNzdWVyLmV4YW1wbGUiLCJjbGFpbXMiOlsiaWF0IiwiZXhwIiwiZmFtaWx5X25hbWUi LCJnaXZlbl9uYW1lIiwiZW1haWwiLCJhZGRyZXNzIiwiYWdlX292ZXJfMjEiXSwicHJvb 2Zfa2V5Ijp7Imt0eSI6IkVDIiwiY3J2IjoiUC0yNTYiLCJ4IjoiTktSTllCVU1QNVZpLV FfWERpMy01Qzh6SEFNY3VfcFBtcjhHU2RrVVVsZyIsInkiOiJ0aGItdzhtaGFTMl9manZ TcDZGb0hQZVBOOXNGSldIR0F4UmhfbFVXbzB3In0sInByZXNlbnRhdGlvbl9rZXkiOnsi a3R5IjoiRUMiLCJjcnYiOiJQLTI1NiIsIngiOiJIQzlVRTdWeVNuVTRLdGxER29vT0F1T nNPRWw1Sm4xMlVfY2hHdWFSY3ZzIiwieSI6InFEOUdsZUMzOFBQclFsSkI0UDdRSEk3Qj dlM0xqemNtbXlXX1JWNUxWUmMifX0.MTcxNDUyMTYwMA~MTcxNzE5OTk5OQ~IkRvZSI~I kpheSI~ImpheWRvZUBleGFtcGxlLm9yZyI~eyJmb3JtYXR0ZWQiOiIxMjM0IE1haW4gU3 QuXG5Bbnl0b3duLCBDQSAxMjM0NVxuVVNBIiwic3RyZWV0X2FkZHJlc3MiOiIxMjM0IE1 haW4gU3QuIiwibG9jYWxpdHkiOiJBbnl0b3duIiwicmVnaW9uIjoiQ0EiLCJwb3N0YWxf Y29kZSI6MTIzNDUsImNvdW50cnkiOiJVU0EifQ~dHJ1ZQ~~.kVq10Cvsta8kNQphGQtmm DbdATtADBT2dhvkWKydge0TxdaF32rffEP_fkFYr5IFza5CUXUN0A9RBHeP1vg5vQ~SSb KbyzKEfnq6eqW-fR6QsHQrS6HOAu2is7_-SBUcaxLDoIFvn0Cu4HauUm09ymBdX5xIHU0 8gq2_EFhcYKAPw~pwy1wFWM3VDihxdPTrWFWPiGIXFeKaSu-xmJMixZ2pHGlj2pKIxTq9 7Ad9-SZDc8kc9S_OU8fCchIMcOY_0yOw~IdA4jo-Tm5Fo7j_0PNQdmn6FQxH5BbvmTtvJ TCWmxYnf4xM2UII8N2Um_WWLGjJm_rC665HmvJuPmNFif_JywA~h7igZFgMiLCBqkISeK XO-K57WhznZuaNFpmnOPtYcIsa8twlZsRNC5sx_HuMe72UgfVUiEryzW89cmUCokb8TQ~ IQneMikxkNZ_VoHDZzpZOE4RKhI_0EAGQ1QhmrJnPd66iQXO1HSBADKT9xEkU8OTqd_PL 23khNT-EkGQ72-Tpw~sHItG7FuxuT2cqlMmW30H-3jMMFE8sHpwQCniOZqvxT-XLBJ8aC RXW70FRpkLhdzyZ9OQM97L1kgalrL3r7-Kw | Figure: Presentation (SU-ES256, JSON, Compact Serialization) A.2. Example CBOR-Serialized Single-Use CPT This example is meant to mirror the prior compact serialization, using RFC8392 (CWT) and claims from [I-D.maldant-spice-oidc-cwt], illustrated using [I-D.ietf-cbor-edn-literals] (EDN). To simplify this example, the same information is represented as the JPT example above, including the same public and private keys. { / protected header / 1: 1, / alg: "SU-ES256" / 3: 20, / typ: "JPT" (20CPA) / 5: "https://issuer.example", / iss: "https://issuer.example" / 6: [ / claims / 6, / "iat" / 4, / "exp" / 170, / "family_name" (I-D.maldant-spice-oidc-cwt TBD1) / 171, / "given_name" (I-D.maldant-spice-oidc-cwt TBD2) / 179, / "email" (I-D.maldant-spice-oidc-cwt TBD10) / 187, / "address" (I-D.maldant-spice-oidc-cwt TBD18) / "age_over_21" ], 8: { / proof key / 1: 2, / kty : "EC2" / -1: 1, / crv: "P-256" / -2: h'1c2f5413b5724a75382ad9431a8a0e02e36c384979267d7653f7211a' + h'e69172fb', / x / -3: h'a83f4695e0b7f0f3eb425241e0fed01c8ec1ededcb8f37269b25bf45' + h'5e4b5517' / y / }, 9: { / presentation key / 1: 2, / kty: "EC2" / -1: 1, / crv: "P-256" / -2: h'34a44d60150c3f9562f90fd70e2dfee42f331c031cbbfa4f9abf0649' + h'd9145258', / x / -3: h'b616fec3c9a1692dbf7e3bd2a7a1681cf78f37db052561c6031461fe' + h'5516a34c' / y / } } | Figure: Issuer Protected Header (SU-ES256, CBOR) [ / payloads / / iat / 171452160, / exp / 171719999, / family_name / "Doe", / given_name / "Jay", / email / "jaydoe@example.org", / address / { / formatted / 1: "1234 Main St.\nAnytown, CA 12345\nUSA", / street / 2: "1234 Main St.", / locality / 3: "Anytown", / region / 4: "CA", / post code / 5: "90210", / country / 6: "USA" }, / age_over_21 / true ] | Figure: Issuer Payloads (as CBOR array) When signed and serialized, the CPT is represented by the following CBOR (in hex): 8358cda601010314057668747470733a2f2f6973737565722e6578616d706c65 0687060418aa18ab18b318bb6b6167655f6f7665725f323108a4010220012158 201c2f5413b5724a75382ad9431a8a0e02e36c384979267d7653f7211ae69172 fb225820a83f4695e0b7f0f3eb425241e0fed01c8ec1ededcb8f37269b25bf45 5e4b551709a40102200121582034a44d60150c3f9562f90fd70e2dfee42f331c 031cbbfa4f9abf0649d9145258225820b616fec3c9a1692dbf7e3bd2a7a1681c f78f37db052561c6031461fe5516a34c871a0a3827001a0a3c3d3f63446f6563 4a6179726a6179646f65406578616d706c652e6f7267a601782331323334204d 61696e2053742e0a416e79746f776e2c2043412031323334350a555341026d31 323334204d61696e2053742e0367416e79746f776e0462434105653930323130 0663555341f58858408e97670c62a2464ff356c390948b1a9a3af5f45a608985 e581f27ce8f1006400e1212794bee842372b5039d0372c53e5255ac20d07072a a6724a1b59ec8153fd5840fe37baa50799566a29de6238b07a1742891c6e0c8b 983ee8fcfdef561fed46e264e48f3b6c5689c2564281574608dec3203932672b a2aff543abc2c767122172584063d723dd7c69f3ef693c595f1e231c633732bd e65b4e0bd9448249ef26b7e0ae48c6c2538676eb23c676880268914f961b3b19 f5f219f8ac05bb9379f37fa41858406d857b23dcbcf6e8ad56c21269e15a9f7d 9e9a045269a3d620f7cb1493cc5affa109ca3ae53a4fb5f2200fe7b4b573c639 abcd707306c5345574cee49927730b5840c3f787a1afc9c52122c6f45ad55dd2 4ddabdfe404690de202467a5b9e14e7882b41622e125a30c546b7d3eb4bb723a ff4b044bde385681731b53664e591bd1f55840270ba312d36a53787656562e37 c52bdff6313e3db7f6ca1ce18309646dc0844631e9655104387861be1b32c53b 0bbc6704117173ca32a70d88ac853651fd51d05840701911298cdac96ba2569b b76f22fd8ddc2fa45cf0b277d069679bd0f3a7850318d9442a747ccaf0fdfe76 299bae4b8e30117278130a2a1547de7d4158cbea9b5840a8a804c2407509d4db 960f65cf57d30834a5cd96a95bdb5ee11bf6246051b4557de50b0f8d59d5f11e df63e34d1873c95cecff88b8a0198e3339a2a622b1e5fe | Fixtures: Issued Form (SU-ES256, CBOR) The presented form, similarly to the issued form above, is made with the holder conveying the same parameters and the same set of selectively disclosed payloads as the JPT above: { / protected header / 1: 1, / alg: "SU-ES256" / 6: "https://recipient.example.com", / aud / 7: h'912796af43e23e4010d6ace14b1dca54c9d96c2ed40f594822d054412f3ccef8', / nonce / } | Figure: Holder Protected Header (SU-ES256, CBOR) When the appropriate proof is generated, the CPT is serialized into the following CBOR (in hex): 845846a3010106781d68747470733a2f2f726563697069656e742e6578616d70 6c652e636f6d075820912796af43e23e4010d6ace14b1dca54c9d96c2ed40f59 4822d054412f3ccef858cda601010314057668747470733a2f2f697373756572 2e6578616d706c650687060418aa18ab18b318bb6b6167655f6f7665725f3231 08a4010220012158201c2f5413b5724a75382ad9431a8a0e02e36c384979267d 7653f7211ae69172fb225820a83f4695e0b7f0f3eb425241e0fed01c8ec1eded cb8f37269b25bf455e4b551709a40102200121582034a44d60150c3f9562f90f d70e2dfee42f331c031cbbfa4f9abf0649d9145258225820b616fec3c9a1692d bf7e3bd2a7a1681cf78f37db052561c6031461fe5516a34c891a0a3827001a0a 3c3d3f63446f65634a6179726a6179646f65406578616d706c652e6f7267a601 782331323334204d61696e2053742e0a416e79746f776e2c2043412031323334 350a555341026d31323334204d61696e2053742e0367416e79746f776e046243 41056539303231300663555341f5f6f68758408e97670c62a2464ff356c39094 8b1a9a3af5f45a608985e581f27ce8f1006400e1212794bee842372b5039d037 2c53e5255ac20d07072aa6724a1b59ec8153fd584045851b8dda59dc844e8141 21b06b6165e857d595d02a7caaa022f83308ca6a59b9fe784601f1f4aa91b27f 2fca3a5711c8bfb1229a2a1d062d82ea0b25447a645840fe37baa50799566a29 de6238b07a1742891c6e0c8b983ee8fcfdef561fed46e264e48f3b6c5689c256 4281574608dec3203932672ba2aff543abc2c767122172584063d723dd7c69f3 ef693c595f1e231c633732bde65b4e0bd9448249ef26b7e0ae48c6c2538676eb 23c676880268914f961b3b19f5f219f8ac05bb9379f37fa41858406d857b23dc bcf6e8ad56c21269e15a9f7d9e9a045269a3d620f7cb1493cc5affa109ca3ae5 3a4fb5f2200fe7b4b573c639abcd707306c5345574cee49927730b5840c3f787 a1afc9c52122c6f45ad55dd24ddabdfe404690de202467a5b9e14e7882b41622 e125a30c546b7d3eb4bb723aff4b044bde385681731b53664e591bd1f5584027 0ba312d36a53787656562e37c52bdff6313e3db7f6ca1ce18309646dc0844631 e9655104387861be1b32c53b0bbc6704117173ca32a70d88ac853651fd51d0 | Figure: Presented Form (SU-ES256, CBOR) A.3. 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": "ATfH-vblwRHAtSPG1c0Jd0FJDFIlHQ_1D5jdFkuD8dlKYHFR7NiDJSMvoQ7K1 oWSDyz6Hf9hNIiwT5k4SnKTEsaBH0jxwazxbRdfzsNEMkmC_C8ODAuwOOMopsX TLg6v", "y": "CSLMNkZhV3J-6OsjjUHJj6MD_ZatPoHJm5MZnfaoXJ9I7YMAVqhhTKHmek46n 2nKBXEcud9pw3eSAsx23VbGfQqj4bdJGO7qkdttjZrStzr9w0gl567JachZcmN z0QZf", "d": "FnDF7YdPbR_fXRbEnVVvh1t5XDZaT-EwhCJTgfrjLm0" } 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 These components are signed using the private issuer key previously given, which is then representable in the following serialization: eyJraWQiOiJIamZjcHlqdVpRLU84WWUyaFFuTmJUOVJiYm5yb2JwdGRuRXhSMERValU4I iwiYWxnIjoiQkJTIn0.MTcxNDUyMTYwMA~MTcxNzE5OTk5OQ~IkRvZSI~IkpheSI~Imph eWRvZUBleGFtcGxlLm9yZyI~eyJmb3JtYXR0ZWQiOiIxMjM0IE1haW4gU3QuXG5Bbnl0b 3duLCBDQSAxMjM0NVxuVVNBIiwic3RyZWV0X2FkZHJlc3MiOiIxMjM0IE1haW4gU3QuIi wibG9jYWxpdHkiOiJBbnl0b3duIiwicmVnaW9uIjoiQ0EiLCJwb3N0YWxfY29kZSI6MTI zNDUsImNvdW50cnkiOiJVU0EifQ~dHJ1ZQ.gBOmIUUbRtc1XxjfG4CPyqrqOAPFuvtg7m zpkERDhajSLsrjrNR9jrXxxa2k4uJeOloPx4yhemLPZOhisT0DOfCVtn1w-EftqEsq3iM i3oY Figure 12: Issued JWP (BBS, JSON, Compact Serialization) For a presentation with the following presentation header: { "alg": "BBS", "aud": "https://recipient.example.com", "nonce": "wrmBRkKtXjQ" } Figure 13: 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 serialization: eyJhbGciOiJCQlMiLCJhdWQiOiJodHRwczovL3JlY2lwaWVudC5leGFtcGxlLmNvbSIsI m5vbmNlIjoid3JtQlJrS3RYalEifQ.eyJraWQiOiJIamZjcHlqdVpRLU84WWUyaFFuTmJ UOVJiYm5yb2JwdGRuRXhSMERValU4IiwiYWxnIjoiQkJTIn0.MTcxNDUyMTYwMA~MTcxN zE5OTk5OQ~IkRvZSI~IkpheSI~~~.gY7Hb3ZdbmkWjzI_DCqOJqq3vyvqvVi8T0HwBUgz 6IyQxldRKon2AMnF2HG1oklsty7PhR_yRaLMTD8N-_oaRpUGZxIddEFyr33mVT4YxreAu tvUeuKMIj4JiBMhXTYPgo3uYGeAC62fkv7aarq7Ku5OOvNhYTaFEqxoUibpt2RzECW6WI 8W452fY01XtlrlAhOlup5Amyzd3wPiViffRqY2aaWGN8O8dXz_Tb7d4rsWUv04EQg1ZVc dj45nkiuqeubjDYEXeJCt4OIh1sgtlgAiHi9UOr_9xvDPYmVZIrnWeUjzcmXFDUoz15R7 MnUZCN6-xyvMuLl2oy4ZQiWU2JWhSWFjot9Z8NOSwx4y6aQ7pe_gRlqZnkUIwc-OiDj0U HER7nZBgt7tv9ufe3vWpid_fSWJHXLu3-obxtb7F5aj1jrVPbDWqDKQHUv5_SI8EW6jDN SWCZB0o6O7w3BQrGxEXOGyCoU-6wm7AK-mvm4 Figure 14: Presentation JWP (BBS, JSON, Compact serialization) A.4. 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": "SYnFf5rvTjTXqn17cpaJ6-WtBQrdp27h8PXskTBKtXY", "y": "aXb61CiSXsQb012hun68cUczn4TVHbnqrvdFLoUCCCk", "d": "m47JVI153rBlUii22gy_0Xn8JWidGhQZzJEiR_hhEgg" } Figure 15: Issuer private key This is the Issuer's ephemerally generated shared secret: "OgZgwK_kxGo0gdbAlhvFZms-3Rq0ZALX5ZWM8BAfSbM" Figure 16: Shared Secret This is the Holder's presentation private key in the JWK format: { "kty": "EC", "crv": "P-256", "x": "HC9UE7VySnU4KtlDGooOAuNsOEl5Jn12U_chGuaRcvs", "y": "qD9GleC38PPrQlJB4P7QHI7B7e3LjzcmmyW_RV5LVRc", "d": "kppFYxR3QmhzPU6SO3mYiVFRiAX1rffnLf6gNyMPbrE" } Figure 17: 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": "HC9UE7VySnU4KtlDGooOAuNsOEl5Jn12U_chGuaRcvs", "y": "qD9GleC38PPrQlJB4P7QHI7B7e3LjzcmmyW_RV5LVRc" } } Figure 18: 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 19: 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: ikSw8DcG-9dCxvm8PwFx9Uo4X-oZ9D-s-A9Eg4oehwg Figure 20: 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 slot (as payload_{n} in UTF-8 encoded octets) as the input in a HMAC operation. This results in the following set of derived keys: [ "AB13nMuexHac3v2NKHupx3VwvfLgUXZowgs9_IWLf14", "v7ZCz03fkViwX7bXyD3NqyhRMoYN9z4nBEyNSe8NWNY", "qKP8XRx6JYGk52MmW7FrRZhk7IasYVbBCInVzo5kGSQ", "yOj7zYmeKsqpMkksXB6c0nu0ZKbbDBufoU-qI_NPZGo", "TJSwYr1Z9O9ChU3jguttHh6sSfmAjaxmo2ulyikKIFc", "XkLGqBiFtrWPOfigCCVM7GbncuL5niKCwqHuRocGeDM", "x-OgPnEuNLYqQnan2HE-rA4LVQjSqiVkEN0UW45U8jM" ] Figure 21: 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: [ "X6kTLYAK8O3vZJnVhpX4hPt4MPKnuYPnrRK9y7UguGw", "ZanqXa1gtJIyPHaA-ny2Vko1us_62RXgl576Yp7vE_M", "o1VNfWrpnPL9mCqd_zbhZE1MbhgYbOENsgA1dkoJJ2o", "08qfzsDbgRxiLzgGFrAkl4X6jxVGw00XfwN4JAklPw0", "ORZxLqjHpKQJmWU4EFy01HeKO6TkCIv2cnR5vPzSTE8", "Qbpi-Ny9pGD6xFbAif2IIoWlih_EY3prMr0PKIFjH_0", "dfgPg2PrVtV4PlSUWelDfL7VZqWmr-BYPBYoWfFgxGM" ] Figure 22: 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. [ "OEV33ktW1J6hlOxsRi_asH6gGsqN53Lv9vWD3fdcDzEuUqcBcsV58NPEWXyBpCnNv7 nhMgKG87oeYMD-tFdRzg", "MUMWlFo4lA4LFP53xVprhWtllzKLCSHMOqNASNu2WjU" ] Figure 23: Issued Proof (Base64url-Encoded) The final issued JWP in compact serialization is: eyJhbGciOiJNQUMtSDI1NiIsInR5cCI6IkpQVCIsImlzcyI6Imh0dHBzOi8vaXNzdWVyL mV4YW1wbGUiLCJjbGFpbXMiOlsiaWF0IiwiZXhwIiwiZmFtaWx5X25hbWUiLCJnaXZlbl 9uYW1lIiwiZW1haWwiLCJhZGRyZXNzIiwiYWdlX292ZXJfMjEiXSwicHJlc2VudGF0aW9 uX2tleSI6eyJrdHkiOiJFQyIsImNydiI6IlAtMjU2IiwidXNlIjoic2lnbiIsIngiOiJI QzlVRTdWeVNuVTRLdGxER29vT0F1TnNPRWw1Sm4xMlVfY2hHdWFSY3ZzIiwieSI6InFEO UdsZUMzOFBQclFsSkI0UDdRSEk3QjdlM0xqemNtbXlXX1JWNUxWUmMifX0.MTcxNDUyMT YwMA~MTcxNzE5OTk5OQ~IkRvZSI~IkpheSI~ImpheWRvZUBleGFtcGxlLm9yZyI~eyJmb 3JtYXR0ZWQiOiIxMjM0IE1haW4gU3QuXG5Bbnl0b3duLCBDQSAxMjM0NVxuVVNBIiwic3 RyZWV0X2FkZHJlc3MiOiIxMjM0IE1haW4gU3QuIiwibG9jYWxpdHkiOiJBbnl0b3duIiw icmVnaW9uIjoiQ0EiLCJwb3N0YWxfY29kZSI6MTIzNDUsImNvdW50cnkiOiJVU0EifQ~d HJ1ZQ.OEV33ktW1J6hlOxsRi_asH6gGsqN53Lv9vWD3fdcDzEuUqcBcsV58NPEWXyBpCn Nv7nhMgKG87oeYMD-tFdRzg~MUMWlFo4lA4LFP53xVprhWtllzKLCSHMOqNASNu2WjU Figure 24: Issued JWP (MAC-H256, JSON, 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": "kSeWr0PiPkAQ1qzhSx3KVMnZbC7UD1lIItBUQS88zvg" } Figure 25: 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 each payload slot, the holder will provide one of two values as part of the proof value. For a disclosed payload, the holder will provide the corresponding derived key. For a non-disclosed payload, 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: [ "yOMR1Pq07WSlPlq7qT465wwHNm_dD05YHV3kwCEZp6o4lwSeqS42OKdHOr8LFZj3N5 T2HZvmeNa-kozFXj5tow", "OEV33ktW1J6hlOxsRi_asH6gGsqN53Lv9vWD3fdcDzEuUqcBcsV58NPEWXyBpCnNv7 nhMgKG87oeYMD-tFdRzg", "AB13nMuexHac3v2NKHupx3VwvfLgUXZowgs9_IWLf14", "v7ZCz03fkViwX7bXyD3NqyhRMoYN9z4nBEyNSe8NWNY", "qKP8XRx6JYGk52MmW7FrRZhk7IasYVbBCInVzo5kGSQ", "yOj7zYmeKsqpMkksXB6c0nu0ZKbbDBufoU-qI_NPZGo", "ORZxLqjHpKQJmWU4EFy01HeKO6TkCIv2cnR5vPzSTE8", "Qbpi-Ny9pGD6xFbAif2IIoWlih_EY3prMr0PKIFjH_0", "dfgPg2PrVtV4PlSUWelDfL7VZqWmr-BYPBYoWfFgxGM" ] Figure 26: Presentation proof (Base64url-Encoded) The final presented JWP in compact serialization is: eyJhbGciOiJNQUMtSDI1NiIsImF1ZCI6Imh0dHBzOi8vcmVjaXBpZW50LmV4YW1wbGUuY 29tIiwibm9uY2UiOiJrU2VXcjBQaVBrQVExcXpoU3gzS1ZNblpiQzdVRDFsSUl0QlVRUz g4enZnIn0.eyJhbGciOiJNQUMtSDI1NiIsInR5cCI6IkpQVCIsImlzcyI6Imh0dHBzOi8 vaXNzdWVyLmV4YW1wbGUiLCJjbGFpbXMiOlsiaWF0IiwiZXhwIiwiZmFtaWx5X25hbWUi LCJnaXZlbl9uYW1lIiwiZW1haWwiLCJhZGRyZXNzIiwiYWdlX292ZXJfMjEiXSwicHJlc 2VudGF0aW9uX2tleSI6eyJrdHkiOiJFQyIsImNydiI6IlAtMjU2IiwidXNlIjoic2lnbi IsIngiOiJIQzlVRTdWeVNuVTRLdGxER29vT0F1TnNPRWw1Sm4xMlVfY2hHdWFSY3ZzIiw ieSI6InFEOUdsZUMzOFBQclFsSkI0UDdRSEk3QjdlM0xqemNtbXlXX1JWNUxWUmMifX0. MTcxNDUyMTYwMA~MTcxNzE5OTk5OQ~IkRvZSI~IkpheSI~~~.yOMR1Pq07WSlPlq7qT46 5wwHNm_dD05YHV3kwCEZp6o4lwSeqS42OKdHOr8LFZj3N5T2HZvmeNa-kozFXj5tow~OE V33ktW1J6hlOxsRi_asH6gGsqN53Lv9vWD3fdcDzEuUqcBcsV58NPEWXyBpCnNv7nhMgK G87oeYMD-tFdRzg~AB13nMuexHac3v2NKHupx3VwvfLgUXZowgs9_IWLf14~v7ZCz03fk ViwX7bXyD3NqyhRMoYN9z4nBEyNSe8NWNY~qKP8XRx6JYGk52MmW7FrRZhk7IasYVbBCI nVzo5kGSQ~yOj7zYmeKsqpMkksXB6c0nu0ZKbbDBufoU-qI_NPZGo~ORZxLqjHpKQJmWU 4EFy01HeKO6TkCIv2cnR5vPzSTE8~Qbpi-Ny9pGD6xFbAif2IIoWlih_EY3prMr0PKIFj H_0~dfgPg2PrVtV4PlSUWelDfL7VZqWmr-BYPBYoWfFgxGM Figure 27: Presented JWP (MAC-H256, JSON, 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 ]] -10 * Clarify MAC issuance and presentation using new "payload slot" nomenclature. * Define a new binary "Presentation Internal Representation" so that the holder signature protects the entire presentation * Leverage the new "Holder Presentation Algorithm" to allow the holder algorithm to be independant from the signature algorithm used by the issuer * Redefine computation of the "Combined MAC Representation" to more closely match the new Presentation Internal Representation. * Change the MAC algorithm to directly sign the binary Combined MAC Representation rather than convert it to a JWS. * Do not unneccessarily hash the issuer protected header inside the Combined MAC Representation, so that it can provide some manner of domain separation. * Clarify how verifiers are to generate the Combined MAC Representation from available information. * Provider step-by-step instructions for verification of a presentation -09 * Remove JSON serialization * Added CBOR (CPT) example to the appendix using SU-ES256 -08 * Made some additional references normative. * Corrected SU-ES256 issuer protected header including private keys -07 * Changing primary editor * Update registry template for algorithms to account for integer CBOR labels * Restylize initial registry entries for readability * 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. * Combined BBS-PROOF into BBS -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 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 Jeremie Miller Ping Identity Email: jmiller@pingidentity.com