]> JSON Proof Algorithms Ping Identity
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Internet jose jose zkp jwp jws jpa The JSON Proof Algorithms (JPA) specification registers cryptographic algorithms and identifiers to be used with the JSON Web Proof and JSON Web Key (JWK) specifications. It defines IANA registries for these identifiers.
Introduction The JSON Web Proof (JWP) 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/json-web-proofs/json-web-proofs.
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 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 . 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.
Terminology The terms "JSON Web Signature (JWS)", "Base64url Encoding", "Header Parameter", "JOSE Header", "JWS Payload", "JWS Signature", and "JWS Protected Header" are defined by . The terms "JSON Web Proof (JWP)", "JWP Payload", "JWP Proof", and "JWP Protected Header" are defined by . 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.
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 . These differences help support more advanced capabilities such as blinded signatures and predicate proofs.
Algorithm Basics The four principal interactions that every proof algorithm MUST support are [issue](#issue), [confirm](#confirm), [present](#present), and [verify](#verify).
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.
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.
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.
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.
Algorithm Specifications This section defines how to use specific algorithms for JWPs.
Single Use
Editor's Note: This algorithm may be renamed and slightly refactored.
The Single Use (SU) algorithm is based on composing multiple traditional JWS values into a single JWP proof value. 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).
JWS Algorithm The Single Use algorithm is based on using multiple JWS values, all of which are generated with the same JSON Web Algorithm (JWA) for signing. This JWA identifier is included as part of the Single Use identifier for JWP. 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.
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 easily accomplished by the holder using this key to generate a JWS that signs a value the issuer can verify as unique.
Issuer Setup To create a Single Use JWP, the issuer first generates a unique Ephemeral Key using the selected JWS algorithm. This key-pair will be used to sign each of the payloads of a single JWP and then discarded.
Using JWS JSON Web Signatures are used to create all of the signature values used by the SU algorithm. This allows an implementation to use an existing JWS library directly for all necessary cryptographic operations without requiring any additional primitives. Each individual JWS uses a fixed protected header containing only the minimum required alg value. Since this JWS protected header itself is the same for every JWS, it SHOULD be a static value in the form of {"alg":"***"} where *** is the JWA asymmetric signing key algorithm identifier being used. This value is recreated by a verifier using the correct JWA algorithm value included in the SU algorithm identifier. If an implementation uses an alternative JWS protected header than this fixed value, a base64url encoded serialized form of the alternate fixed header MUST be included using the jws_header claim in the issuer protected header.
Issuer Protected Header The JWK of the issuer's Ephemeral Key MUST be included in the issuer protected header with the property name of proof_jwk and contain only the REQUIRED values to represent the public key. The holder's Presentation Key JWK MUST be included in issuer protected header using the presentation_jwk claim. The final issuer protected header is then used directly as the body of a JWS and signed using the issuer's Stable Key. The resulting JWS signature value unencoded octet string is the first value in the JWP proof. In various examples in this specification, the octet string serialized issuer header is referenced as issuer_header.
Payloads Each JWP payload is processed in order and signed as a JWS body using the issuer's Ephemeral Key. The resulting JWS signature value unencoded octet string is appended to the JWP proof. The proof value as an octet string will have a total length that is the sum of the fixed length of the issuer protected header signature plus the fixed length of each of the payload Ephemeral Key signatures. For example, the signature for the ES256 algorithm is 64 octets and for a JWP with five payloads the total proof value length would be 64 * (1 + 5) = 384 octets).
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 claim 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 claims SHOULD NOT contain values that are common across multiple presentations and SHOULD be unique to a single presentation and verifier. In various examples in this specification, the octet string serialized presentation header is referenced as presentation_header.
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 value when presenting it to a verifier. 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 value is always the holder's Presentation Key signature of the presentation protected header, constructed identically to the issuer protected header by using the serialized JSON value octet string as the JWS body. 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. The two header signatures are then followed by only the issuer's Ephemeral Key signatures for each payload that is disclosed. The order of the payload signatures is preserved and MUST be in the same order as the included disclosed payloads in the presented JWP. Non-disclosed payloads will NOT have a signature value included. For example, if the second and fifth payloads are hidden then the holder's derived proof value would be of the length 64 * (1 + 1 + the 1st, 2nd, and 4th payload signatures) = 320 octets. 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.
Verification The verifier MUST verify the issuer protected header against the first matching JWS signature part in the proof value using the issuer's Stable Key. It MUST also verify the presentation protected header against the second JWS signature part in the proof value using the holder's Presentation Key as provided in the presentation_jwk claim in the issuer protected header. With the headers verified, the issuer's Ephemeral Key as given in the issuer protected header proof_jwk claim can then be used to verify each of the disclosed payload signatures.
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".
Example See the example in the appendix of .
BBS The BBS Signature Scheme 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.
JPA Algorithms The BBS-DRAFT-5 alg parameter value in the issuance protected header corresponds to a ciphersuite identifier of BBS_BLS12381G1_XMD:SHA-256_SSWU_RO_H2G_HM2S_. The BBS-PROOF-DRAFT-5 alg parameter value in the presentation protected header corresponds to the same ciphersuite, but used in presentation form.
Key Format The key used for the BBS-DRAFT-5 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 The JWK form of this key is an OKP type with a curve of BLs12381G2, with x being the BASE64URL-encoded form of the output of point_to_octets_E2. The use of this curve is described in .
BBS private key in JWK format
There is no additional holder key necessary for presentation proofs.
Issuance Issuance is performed using the Sign operation from . 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 the issuance proof, to be used along with the protected header and payloads to serialize the JWP. As an example, consider following protected header and array of payloads:
Example issuer protected header
Example issuer payloads (as members of a JSON array)
These components along with the private issuer key previously given would be representable in the following serializations:
Issued JWP (JSON serialization)
Issued JWP (compact serialization)
Issuance Proof Verification Holder verification of the signature on issuance form is performed using the Verify operation from . 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.
Presentation Derivation of a presentation is done by the holder using the ProofGen operation from . 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. 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. For example, given the following presentation header:
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 JWP (JSON serialization)
Presentation JWP (compact serialization)
Presentation Verification Verification of a presentation is done by the verifier using the ProofVerify operation from . 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.
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 JWS-based JPA, 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 or KMAC. It uses traditional public-key based signatures to verify the authenticity of the issuer and holder.
Holder Setup Prior to the issuer creating a new JWP, it must have presentation binding information provided by the holder. This enables the holder to perform replay prevention while presenting the JWP. The presentation key used by the holder must be transferred to the issuer and verified, likely through a challenge and self-signing mechanism. If the holder requires unlinkability, it must also generate a new key that is verified and bound to each new JWP. How these holder presentation keys are transferred and verified is out of scope of this specification. Protocols such as OpenID Connect can be used to accomplish this. What is required by this definition is that the holder's presentation key MUST be included in the issuer's protected header using the pjwk claim with a JWK as the value.
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.
Issuer Protected Header The holder's presentation key JWK MUST be included in the issuer protected header using the pjwk claim. The issuer MUST validate that the holder has possession of this key through a trusted mechanism such as verifying the signature of a unique nonce value from the holder. For consistency, the issuer header is also protected by a MAC by using the fixed value "issuer_header" as the input key. The issuer header JSON is serialized using UTF-8 and encoded with base64url into an octet array. The final issuer header MAC is generated from the octet array and the fixed key, and the resulting value becomes the first input into the larger octet array that will be signed by the issuer.
Payloads A unique key is generated for each payload using the MAC with the Shared Secret as the key and the values "payload_X" where "X" is replaced by the zero-based array index of the payload, for example "payload_0", "payload_1", etc. Each payload is serialized using UTF-8 and encoded with base64url into an octet array. The generated key for that payload based on its index is used to generate the MAC for the payload's encoded octet array. The resulting value is appended to the larger octet array that will be signed by the issuer.
Issuer Proof The issuer proof consists of two items appended together: the issuer's signature of the appended array of MACs and the Shared Secret used to generate the set of payload keys. To generate the signature, the array containing the final MAC of the issuer protected header followed by all of the payload MACs appended in order is used as the input to a new JWS. The issuer signs the JWS using its stable public key and a fixed header containing the alg associated with MAC algorithm in use. jws_header = '{"alg":"ES256"}' The resulting signature is decoded and used as the first item in the issuer proof value. The octet array of the Shared Secret is appended, resulting in the final issuer proof value. issuer_proof = [jws_signature, shared_secret]
Presentation Protected Header See the JWS Presentation Protected Header section.
Presentation
Editor's Note: The current definition here is incomplete, the holder's signature needs to also incorporate the presented proof.
The presentation proof is constructed as a large octet array containing multiple appended items similar to the issuer proof value. The first item is the JWS decoded signature value generated when the holder uses the presentation key to sign the presentation header. The second item is the issuer signature from the issuer's proof value. These two signatures are then followed by a MAC value for each payload. The MAC values used will depend on whether that payload has been disclosed or is hidden. Disclosed payloads will include the MAC key input, and hidden payloads will include only their final MAC value. The size of this value will depend on the underlying cryptographic algorithms. For example, MAC-H256 uses the ES256 JWS with a decoded signature of 64 octets, and for a JWP with five payloads using HMAC-SHA256 the total presentation proof value length would be 64 + 64 + (5 * 32) = 288 octets.
Verifier Setup To verify that the presentation was protected from replay attacks, the verifier must be able to validate the presentation protected header. This involves the following steps:
  1. JSON parse the presentation header
  2. Validate the contained nonce claim
  3. JSON parse the issuer header
  4. Validate the contained pjwk claim
  5. Create a JWS using the correct fixed header with alg value and the presentation header as the body
  6. Remove the presentation_signature from the beginning of the presentation_proof octet array
  7. Validate the JWS using the JWK from the pjwk claim and the presentation_signature value
Next, the verifier must validate all of the disclosed payloads using the following steps:
  1. JSON parse the issuer header
  2. Resolve the kid using a trusted mechanism to obtain the correct issuer JWK
  3. Remove the issuer_signature from the beginning of the remaining presentation_proof octet array (after the presentation_signature was removed)
  4. Perform the MAC on the presented issuer_header value using the "issuer_header" value as the input key
  5. Store the resulting value as the first entry in a new jws_payload octet array
  6. Iterate on each presented payload (disclosed or hidden)
    1. Extract the next hash value from the remaining presentation_proof octet array
    2. If the payload was disclosed: perform a MAC using the given hash value as the input key and append the result to the jws_payload octet array
    3. If the payload was hidden: append the given hash value to the jws_payload octet array
  7. Create a JWS using a header containing the alg parameter along with the generated jws_payload value as the payload
  8. Validate the JWS using the resolved issuer JWK and the extracted issuer_signature value
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
Example The following example uses the MAC-H256 algorithm. This is the Signer's stable private key in the JWK format:
issuer-private-jwk
This is the Signer's generated Shared Secret:
mac-shared-secret
This is the Holder's presentation private key in the JWK format:
holder-presentation-jwk
The first MAC is generated using the key issuer_header and the base64url-encoded issuer protected header, resulting in this octet array:
mac-issuer-header-mac
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 the input:
mac-issuer-keys
The first payload is the string "Doe" with the octet sequence of [ 34, 68, 111, 101, 34 ] and base64url-encoded as IkRvZSI. The second payload is the string "Jay" with the octet sequence of [ 34, 74, 97, 121, 34 ] and base64url-encoded as IkpheSI. The third payload is the string "jaydoe@example.org" with the octet sequence of [ 34, 106, 97, 121, 100, 111, 101, 64, 101, 120, 97, 109, 112, 108, 101, 46, 111, 114, 103, 34 ] and base64url-encoded as ImpheWRvZUBleGFtcGxlLm9yZyI. The fourth payload is the string 42 with the octet sequence of [ 52, 50 ] and base64url-encoded as NDI. A MAC is generated for each payload using the generated key for its given index, resulting in an array of MACs:
mac-issuer-macs
Concatenating the issuer protected header MAC with the array of payload MACs produces a single octet array that is signed using the issuer's stable key, resulting in the following signature:
mac-issuer-signature
The original shared secret octet string is then concatenated to the end of the issuer signature octet string and the result is base64url-encoded as the issuer's proof value. The final issued JWP in JSON serialization is:
mac-issued-jwp
The same JWP in compact serialization:
mac-issued-compact
Next, we show the presentation of the JWP with selective disclosure. We start with this presentation header using a nonce provided by the Verifier:
mac-presentation-header
When signed with the holder's presentation key, the resulting signature octets are:
mac-presentation-header-signature
Then by applying selective disclosure of only the given name and age claims (family name and email hidden, payload array indexes 0 and 2), the holder builds a mixed array of either the payload key (if disclosed) or MAC (if hidden):
mac-presentation-keyormac
The final presented proof value is generated by concatenating first the presentation header signature octet string, followed by the issuer signature octet string, then followed by the mixed array of keys and MACs:
mac-presentation-proof
The resulting presented JWP in JSON serialization is:
mac-presentation-jwp
The same JWP in compact serialization:
mac-presentation-compact
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
IANA Considerations The following registration procedure is used for all the registries established by this specification. Values are registered on a Specification Required 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.
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.
Registration Template
  • Algorithm Name: The name requested (e.g., "SU-ES256"). This name is a case-sensitive ASCII string. Names may not match other registered names in a case-insensitive manner unless the Designated Experts state that there is a compelling reason to allow an exception.
  • Algorithm Description: Brief description of the algorithm (e.g., "Single-Use JWP using ES256").
  • 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 non-authenticated encryption algorithms or other 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.
Initial Registry Contents
  • Algorithm Name: SU-ES256
  • Algorithm Description: Single-Use JWP using ES256
  • Algorithm Usage Location(s): Issued, Presented
  • JWP Implementation Requirements: Recommended
  • Change Controller: IETF
  • Specification Document(s): of this specification
  • Algorithm Analysis Documents(s): n/a
  • Algorithm Name: SU-ES384
  • Algorithm Description: Single-Use JWP using ES384
  • Algorithm Usage Location(s): Issued, Presented
  • JWP Implementation Requirements: Optional
  • Change Controller: IETF
  • Specification Document(s): of this specification
  • Algorithm Analysis Documents(s): n/a
  • Algorithm Name: SU-ES512
  • Algorithm Description: Single-Use JWP using ES512
  • Algorithm Usage Location(s): Issued, Presented
  • JWP Implementation Requirements: Optional
  • Change Controller: IETF
  • Specification Document(s): of this specification
  • Algorithm Analysis Documents(s): n/a
  • Algorithm Name: BBS-DRAFT-5
  • 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): of this specification
  • Algorithm Analysis Documents(s): n/a
  • Algorithm Name: BBS-PROOF-DRAFT-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): of this specification
  • Algorithm Analysis Documents(s): n/a
  • Algorithm Name: MAC-H256
  • 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): of this specification
  • Algorithm Analysis Documents(s): n/a
  • Algorithm Name: MAC-H384
  • 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): of this specification
  • Algorithm Analysis Documents(s): n/a
  • Algorithm Name: MAC-H512
  • 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): of this specification
  • Algorithm Analysis Documents(s): n/a
  • Algorithm Name: MAC-K25519
  • 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): of this specification
  • Algorithm Analysis Documents(s): n/a
  • Algorithm Name: MAC-K448
  • 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): of this specification
  • Algorithm Analysis Documents(s): n/a
  • Algorithm Name: MAC-H256K
  • 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): of this specification
  • Algorithm Analysis Documents(s): n/a
Header Parameter Names Registration This section registers the following Header Parameter names defined by this specification in the IANA "JSON Web Proof Header Parameters" registry established by .
Registry Contents
  • Header Parameter Name: proof_jwk
  • Header Parameter Description: Issuer's Ephemeral Key
  • Header Parameter Usage Location(s): Issued
  • Change Controller: IETF
  • Specification Document(s): of this specification
  • Header Parameter Name: presentation_jwk
  • Header Parameter Description: Holder's Presentation Key
  • Header Parameter Usage Location(s): Issued
  • Change Controller: IETF
  • Specification Document(s): of this specification
References Normative References Informative References Verifiable Credentials Data Model 2.0 Digital Bazaar OpenLink Software W3C Invited Expert Block
Acknowledgements This work was incubated in the DIF Applied Cryptography Working Group. 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 .
Document History [[ To be removed from the final specification ]] -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