| Internet-Draft | json-proof-algorithms | November 2025 |
| Jones, et al. | Expires 8 May 2026 | [Page] |
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.¶
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/.¶
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This Internet-Draft will expire on 8 May 2026.¶
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.¶
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.¶
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.¶
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 Header" are defined by [I-D.ietf-jose-json-web-proof].¶
These terms are defined by this specification:¶
JWP defines a container binding together a 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.¶
The four principal interactions that every proof algorithm MUST support are issue, confirm, present, and verify.¶
The JWP is first created as the output of a JPA's issue operation.¶
Every algorithm MUST support a JSON issuer 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.¶
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 Header and all payloads. If given a presented JWP instead of an issued one, the confirm process MUST return an error.¶
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 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 Header that provides replay protection.¶
Performed by the verifier to verify the 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 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.¶
This section defines how to use specific algorithms for JWPs.¶
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).¶
The Single Use algorithm uses multiple signing keys to protect the Header as well as individual payloads of an Issued JWP. The issuer uses a stable public key to sign each Header, and a per-JWP ephemeral key (conveyed within the 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 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 asymmetric signing algorithms, so that each signature can be verified without sharing any private values between the parties.¶
In order to support the protection of a presentation by a holder to a verifier, the holder MUST use a Holder Presentation Key during the issuance and the presentation of every Single Use JWP. This Holder Presentation Key MUST be generated and used for only one JWP if unlinkability is desired.¶
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 determine an appropriate holder presentation algorithm
corresponding to the holder presentation key. If the holder and
verifier cannot be assumed to know this algorithm is the appropriate
choice for a given holder presentation key, this value MUST be conveyed
in the hpa Issuer Header.¶
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.¶
Each individual payload is signed using the selected internal algorithm using the Ephemeral Key.¶
The Issuer's Ephemeral Key MUST be included via the Issuer Ephemeral Key Header Parameter.¶
The Holder's Presentation Key MUST be included via the Holder 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 Header is signed using the appropriate internal signing algorithm for the given fully-specified single use algorithm, using the issuer's Stable Key.¶
Each JWP payload is processed in order and signed using the given JWA using the issuer's Ephemeral Key.¶
The proof value is an octet string array. The first entry is the octet string of the Issuer Header signature, with an additional entry for each payload signature.¶
To generate a new presentation, the holder first creates a Presentation
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 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 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 Header MUST contain the same Algorithm protected header as the Issuer Header. The Holder Presentation Algorithm Header Parameter MUST NOT be included.¶
The holder derives a new proof as part of presentation. The holder will also use these components to generate a presentation 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 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 Presentation Header, Issuer 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:¶
The presentation internal representation would be calculated with these three proof components, while the final presentation would have an additional fourth 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.¶
Verification is performed using the following steps.¶
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".¶
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:¶
0x84 5B¶
0x5B¶
0x9B¶
For each payload representation:¶
0x9B¶
The number of proof components as specified by the algorithm¶
For each proof component, append:¶
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.¶
The BBS algorithm corresponds to a cipher suite identifier of
BBS_BLS12381G1_XMD:SHA-256_SSWU_RO_.¶
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.¶
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 Header octets as header, and the array of payload
octet string as messages.¶
The octets resulting from this operation form a single octet string in the issuance proof array, to be used along with the Header and payloads to serialize the JWP.¶
Holder verification of the signature on issuance form is performed using
the Verify operation from [@!I-D.irtf-cfrg-bbs-signatures, section
3.5.2].¶
This operation utilizes the issuer's public key as PK, the proof as
signature, the Header octets as header and the array of
payload octets as messages.¶
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
Header as header, the issuance proof as signature, the
issuance payloads as messages, and the holder's Presentation 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 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.¶
Verification of a presentation is done by the verifier using the
ProofVerify operation from [@!I-D.irtf-cfrg-bbs-signatures, Section
3.5.4].¶
This operation utilizes the issuer's public key as PK, the Issuer
Header as header, the issuance proof as signature, the
holder's Presentation 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.¶
The Message Authentication Code (MAC) JPA uses a MAC to both generate ephemeral 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 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. It uses traditional public key-based signatures to verify the authenticity of the issuer and holder.¶
In order to support the protection of a presentation by a holder to a verifier, the holder MUST use a Holder Presentation Key during the issuance and the presentation of every MAC JWP. This Holder Presentation Key MUST be generated and used for only one JWP if unlinkability is desired.¶
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 holder's presentation key MUST be included in the Issuer Header using the Holder Presentation Key Header Parameter.¶
The issuer MUST determine an appropriate holder presentation algorithm corresponding to the holder presentation key. If the holder and verifier cannot be assumed to know this algorithm is the appropriate choice for a given holder presentation key, this value MUST be conveyed in the Holder Protected Algorithm Header Parameter.¶
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 with 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.¶
The combined MAC representation is a single octet string representing the MAC values of the Issuer 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 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:¶
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:¶
The binary representation is created by appending data into a single octet string in the following order:¶
The Holder's Presentation Key MUST be included via the Holder 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 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.¶
See the Presentation Header section given for Single Use algorithms.¶
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¶
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 Presentation Header, Issuer Header, payload slots (distinguishing which are being disclosed) and above 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.¶
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.¶
Verification is performed using the following steps.¶
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¶
Editor's Note: This will follow once the algorithms defined here have become more stable.¶
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.¶
This specification establishes the IANA "JSON Web Proof Algorithms"
registry for values of the JWP alg (algorithm) parameter in 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.¶
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.¶
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.¶
1). CBOR Labels may not match
other registered labels unless the Designated Experts state that there
is a compelling reason to allow an exception.¶
Issued or Presented. Other values may be used with the
approval of a Designated Expert.¶
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.¶
SU-ES256¶
SU-ES384¶
SU-ES512¶
BBS¶
BBS_BLS12381G1_XMD:SHA-256_SSWU_RO_H2G_HM2S_¶
MAC-H256¶
MAC-H256 uses HMAC SHA-256 as the MAC, and
ECDSA using P-256 and SHA-256 for the signatures¶
MAC-H384¶
MAC-H384 uses HMAC SHA-384 as the MAC, and
ECDSA using P-384 and SHA-384 for the signatures¶
MAC-H512¶
MAC-H512 uses HMAC SHA-512 as the MAC, and
ECDSA using P-521 and SHA-512 for the signatures¶
MAC-K25519¶
MAC-K25519 uses KMAC SHAKE128 as the MAC,
and EdDSA using Curve25519 for the signatures¶
MAC-K448¶
MAC-K448 uses KMAC SHAKE256 as the MAC, and
EdDSA using Curve448 for the signatures¶
MAC-H256K¶
MAC-H256K uses HMAC SHA-256 as the MAC, and
ECDSA using secp256k1 and SHA-256 for the signatures¶
The following examples use algorithms defined in JSON Proof Algorithms and also contain the keys used, so that implementations can validate these samples.¶
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": "artZdEJNwOokMjb9QYAok2F5rdVGIEW8kWT6CdWxPD4",
"y": "U1GzkINYTblBJba6Y3BbvqUHVyLK9IceYwPRiW_5e-o",
"d": "JhsPV_JouEIELEfpK1ZePNDDhGjcI3HutBer8WMWE0M"
}
This is the ephemeral private key used in this example in the JWK format:¶
{
"kty": "EC",
"crv": "P-256",
"x": "pO4UZ5y_8PfmFJ4Y7hQOGDfjVhwWjowaQosjQt9z--4",
"y": "cxBiJSEU3DUAm4N2LmzSnQsjQ5ZhLB-9FYB-7TDDh90",
"d": "uPEtjQqG5aBMiHf7XF3Ypz-WEVUfrCVWRIdmkWPSpx4"
}
This is the Holder's presentation private key used in this example in the JWK format:¶
{
"kty": "EC",
"crv": "P-256",
"x": "R109a_ePkizJPQBDAecjgct4-m6QpiH0wtLh17QaHLg",
"y": "VGMtWRNw75qshHTZs5Y4JvwAWuRcxnuNghtuyU1GTIs",
"d": "eFR6wFUCw4hhMh5YRuhNt3yP5XIKyJBfrwDKeRKbey4"
}
The 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",
"hpa": "ES256",
"claims": [
"iat",
"exp",
"family_name",
"given_name",
"email",
"address",
"age_over_21"
],
"iek": {
"kty": "EC",
"crv": "P-256",
"x": "pO4UZ5y_8PfmFJ4Y7hQOGDfjVhwWjowaQosjQt9z--4",
"y": "cxBiJSEU3DUAm4N2LmzSnQsjQ5ZhLB-9FYB-7TDDh90"
},
"hpk": {
"kty": "EC",
"crv": "P-256",
"x": "R109a_ePkizJPQBDAecjgct4-m6QpiH0wtLh17QaHLg",
"y": "VGMtWRNw75qshHTZs5Y4JvwAWuRcxnuNghtuyU1GTIs"
}
}
eyJhbGciOiJTVS1FUzI1NiIsInR5cCI6IkpQVCIsImlzcyI6Imh0dHBzOi8vaXNzdWVyL mV4YW1wbGUiLCJocGEiOiJFUzI1NiIsImNsYWltcyI6WyJpYXQiLCJleHAiLCJmYW1pbH lfbmFtZSIsImdpdmVuX25hbWUiLCJlbWFpbCIsImFkZHJlc3MiLCJhZ2Vfb3Zlcl8yMSJ dLCJpZWsiOnsia3R5IjoiRUMiLCJjcnYiOiJQLTI1NiIsIngiOiJwTzRVWjV5XzhQZm1G SjRZN2hRT0dEZmpWaHdXam93YVFvc2pRdDl6LS00IiwieSI6ImN4QmlKU0VVM0RVQW00T jJMbXpTblFzalE1WmhMQi05RllCLTdURERoOTAifSwiaHBrIjp7Imt0eSI6IkVDIiwiY3 J2IjoiUC0yNTYiLCJ4IjoiUjEwOWFfZVBraXpKUFFCREFlY2pnY3Q0LW02UXBpSDB3dEx oMTdRYUhMZyIsInkiOiJWR010V1JOdzc1cXNoSFRaczVZNEp2d0FXdVJjeG51TmdodHV5 VTFHVElzIn19
The Single Use algorithm utilizes multiple individual JWS Signatures.
Each signature value is generated by creating a JWS with a single
Header with the associated alg value. In this example, the
fixed Header used for each JWS is the serialized JSON Object
{"alg":"ES256"}. This 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
]
The compact serialization of the same JPT is:¶
eyJhbGciOiJTVS1FUzI1NiIsInR5cCI6IkpQVCIsImlzcyI6Imh0dHBzOi8vaXNzdWVyL mV4YW1wbGUiLCJocGEiOiJFUzI1NiIsImNsYWltcyI6WyJpYXQiLCJleHAiLCJmYW1pbH lfbmFtZSIsImdpdmVuX25hbWUiLCJlbWFpbCIsImFkZHJlc3MiLCJhZ2Vfb3Zlcl8yMSJ dLCJpZWsiOnsia3R5IjoiRUMiLCJjcnYiOiJQLTI1NiIsIngiOiJwTzRVWjV5XzhQZm1G SjRZN2hRT0dEZmpWaHdXam93YVFvc2pRdDl6LS00IiwieSI6ImN4QmlKU0VVM0RVQW00T jJMbXpTblFzalE1WmhMQi05RllCLTdURERoOTAifSwiaHBrIjp7Imt0eSI6IkVDIiwiY3 J2IjoiUC0yNTYiLCJ4IjoiUjEwOWFfZVBraXpKUFFCREFlY2pnY3Q0LW02UXBpSDB3dEx oMTdRYUhMZyIsInkiOiJWR010V1JOdzc1cXNoSFRaczVZNEp2d0FXdVJjeG51TmdodHV5 VTFHVElzIn19.MTcxNDUyMTYwMA~MTcxNzE5OTk5OQ~IkRvZSI~IkpheSI~ImpheWRvZU BleGFtcGxlLm9yZyI~eyJmb3JtYXR0ZWQiOiIxMjM0IE1haW4gU3QuXG5Bbnl0b3duLCB DQSAxMjM0NVxuVVNBIiwic3RyZWV0X2FkZHJlc3MiOiIxMjM0IE1haW4gU3QuIiwibG9j YWxpdHkiOiJBbnl0b3duIiwicmVnaW9uIjoiQ0EiLCJwb3N0YWxfY29kZSI6MTIzNDUsI mNvdW50cnkiOiJVU0EifQ~dHJ1ZQ.2BIn2R3quYl9EaIUSslbDZWtfaNeu93FjTmgg0MC 0nw2E5baPGOjzUDZiWJTAINdxqMnShJiNUBc34lXLzfqtg~XZKw4BtNayT8canDhIXUgk uN0NcZdbMvn1kGZfvPdmbtgbebLkSBlCi9mkrKBA800B-0lzYzKe_MtKH6_5Kwmw~ZBHH vrvebgp8yDTRiO3evvHY6QnFdbOSfY3C8NVmCOjnEpxcWvVCpX7DjBTuM2Tk4IS-nqFwG jaDOGLOdupIaA~z65fBUSDiVAv3ajP9R9vBtg8yN9fPjANm5n89lXc1O0zQXH1uFmxL6N jwFHjD0sB5-iulvsdyMuf_viXeSyg4Q~9XsRJmqqz1aXxVxDb2Nsx_o1K1EiSvKkMmqvo LZUVFa-VCZ2iB4SgMOHSr9T8j8LydrhonI7_xcOPkiBXZRlww~i8mQMVEV8YuaRL70_J- PgoasreZy9mxykzhhIHiiP_3DW0xnpXwdaWdfwzjH_mTBAQTA6fAeMf5vPTQn0Pz0qQ~M 3bcXhopAPLTw6VZFacV7KLQhcTEKgoeFw6jlPWbChxAkyVybDZFUCQIWLv8rdMevrpcBk FyFfBQL4KYZ7hNVQ~k9ocfDHyGeZfA5fEswOu3fW_SR7J0yBbFJ6YE-byfkW6EKjVTjRr I0k0QOXxqqi26fS_t-u33t5xHqSQxtJ3FQ
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": "xTtt15VJ9gn0_6--f_OHFeQWEhFuDb_TsHAl6UexKvA"
}
eyJhbGciOiJTVS1FUzI1NiIsImF1ZCI6Imh0dHBzOi8vcmVjaXBpZW50LmV4YW1wbGUuY 29tIiwibm9uY2UiOiJ4VHR0MTVWSjlnbjBfNi0tZl9PSEZlUVdFaEZ1RGJfVHNIQWw2VW V4S3ZBIn0
We apply selective disclosure of only the given name and age claims (family name and email hidden), and remove the proof components corresponding to these entries.¶
Using the selectively disclosed information, we generate the presentation internal representation. Using that and the selectively disclosed payloads, we get the following presented JPT in compact serialization:¶
eyJhbGciOiJTVS1FUzI1NiIsImF1ZCI6Imh0dHBzOi8vcmVjaXBpZW50LmV4YW1wbGUuY 29tIiwibm9uY2UiOiJ4VHR0MTVWSjlnbjBfNi0tZl9PSEZlUVdFaEZ1RGJfVHNIQWw2VW V4S3ZBIn0.eyJhbGciOiJTVS1FUzI1NiIsInR5cCI6IkpQVCIsImlzcyI6Imh0dHBzOi8 vaXNzdWVyLmV4YW1wbGUiLCJocGEiOiJFUzI1NiIsImNsYWltcyI6WyJpYXQiLCJleHAi LCJmYW1pbHlfbmFtZSIsImdpdmVuX25hbWUiLCJlbWFpbCIsImFkZHJlc3MiLCJhZ2Vfb 3Zlcl8yMSJdLCJpZWsiOnsia3R5IjoiRUMiLCJjcnYiOiJQLTI1NiIsIngiOiJwTzRVWj V5XzhQZm1GSjRZN2hRT0dEZmpWaHdXam93YVFvc2pRdDl6LS00IiwieSI6ImN4QmlKU0V VM0RVQW00TjJMbXpTblFzalE1WmhMQi05RllCLTdURERoOTAifSwiaHBrIjp7Imt0eSI6 IkVDIiwiY3J2IjoiUC0yNTYiLCJ4IjoiUjEwOWFfZVBraXpKUFFCREFlY2pnY3Q0LW02U XBpSDB3dExoMTdRYUhMZyIsInkiOiJWR010V1JOdzc1cXNoSFRaczVZNEp2d0FXdVJjeG 51TmdodHV5VTFHVElzIn19.MTcxNDUyMTYwMA~MTcxNzE5OTk5OQ~IkRvZSI~IkpheSI~ ImpheWRvZUBleGFtcGxlLm9yZyI~eyJmb3JtYXR0ZWQiOiIxMjM0IE1haW4gU3QuXG5Bb nl0b3duLCBDQSAxMjM0NVxuVVNBIiwic3RyZWV0X2FkZHJlc3MiOiIxMjM0IE1haW4gU3 QuIiwibG9jYWxpdHkiOiJBbnl0b3duIiwicmVnaW9uIjoiQ0EiLCJwb3N0YWxfY29kZSI 6MTIzNDUsImNvdW50cnkiOiJVU0EifQ~dHJ1ZQ~~.2BIn2R3quYl9EaIUSslbDZWtfaNe u93FjTmgg0MC0nw2E5baPGOjzUDZiWJTAINdxqMnShJiNUBc34lXLzfqtg~XZKw4BtNay T8canDhIXUgkuN0NcZdbMvn1kGZfvPdmbtgbebLkSBlCi9mkrKBA800B-0lzYzKe_MtKH 6_5Kwmw~ZBHHvrvebgp8yDTRiO3evvHY6QnFdbOSfY3C8NVmCOjnEpxcWvVCpX7DjBTuM 2Tk4IS-nqFwGjaDOGLOdupIaA~z65fBUSDiVAv3ajP9R9vBtg8yN9fPjANm5n89lXc1O0 zQXH1uFmxL6NjwFHjD0sB5-iulvsdyMuf_viXeSyg4Q~9XsRJmqqz1aXxVxDb2Nsx_o1K 1EiSvKkMmqvoLZUVFa-VCZ2iB4SgMOHSr9T8j8LydrhonI7_xcOPkiBXZRlww~i8mQMVE V8YuaRL70_J-PgoasreZy9mxykzhhIHiiP_3DW0xnpXwdaWdfwzjH_mTBAQTA6fAeMf5v PTQn0Pz0qQ~vFxZOk4y77mbMAGqMm5IBctzgAZVIzu14UV5dMncKpNnNaUidIfQKmCJiZ JbbYLaI_G0sdWmORPKSmU1ZPEk6Q¶
Figure: Presentation (SU-ES256, JSON, Compact Serialization)¶
This example is meant to mirror the prior compact serialization, using RFC8392 and claims from [I-D.ietf-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: { / iek /
1: 2, / kty : "EC2" /
-1: 1, / crv: "P-256" /
-2: h'a4ee14679cbff0f7e6149e18ee140e1837e3561c168e8c1a428b2342' +
h'df73fbee', / x /
-3: h'731062252114dc35009b83762e6cd29d0b234396612c1fbd15807eed' +
h'30c387dd' / y /
},
9: { / hpk /
1: 2, / kty: "EC2" /
-1: 1, / crv: "P-256" /
-2: h'475d3d6bf78f922cc93d004301e72381cb78fa6e90a621f4c2d2e1d7' +
h'b41a1cb8', / x /
-3: h'54632d591370ef9aac8474d9b3963826fc005ae45cc67b8d821b6ec9' +
h'4d464c8b' / y /
},
10: -9 / hpa: "ESP256" (I-D.ietf-jose-fully-specified-algorithms TBD-9) /
}
¶
Figure: Issuer 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):¶
8358cfa701010314057668747470733a2f2f6973737565722e6578616d706c65 0687060418aa18ab18b318bb6b6167655f6f7665725f323108a4010220012158 20a4ee14679cbff0f7e6149e18ee140e1837e3561c168e8c1a428b2342df73fb ee225820731062252114dc35009b83762e6cd29d0b234396612c1fbd15807eed 30c387dd09a401022001215820475d3d6bf78f922cc93d004301e72381cb78fa 6e90a621f4c2d2e1d7b41a1cb822582054632d591370ef9aac8474d9b3963826 fc005ae45cc67b8d821b6ec94d464c8b0a28871a0a3827001a0a3c3d3f63446f 65634a6179726a6179646f65406578616d706c652e6f7267a601782331323334 204d61696e2053742e0a416e79746f776e2c2043412031323334350a55534102 6d31323334204d61696e2053742e0367416e79746f776e046243410565393032 31300663555341f5885840d0a168fe890e5f97ebe9072f03800029d11ca33b92 07466a3e9827d2edf5c7fa825f68e60e322539a9288407582c519352f328cd9b 60141353ef1dfd6ced2df25840680338bc860e85413705e8cc2929cadd66398b 70137a49a93b2e69a325dc64fc93626d6a54c9b359623dbe5f438e21b1e10ecf 7cc7dabd946ceaf70efb791ad758402b6754416cee0e0093260edf6746b7513e 2fa9daa917a65bd1a5dc87f1604ab0742fc34e253b385a8e9b77489958e0ed2a 0c1f2449a3c90b605a08e7d9e5519658404f67e9d36c3de27f7d732cac9166d7 1e3dcaa2d248885dbcc2295516e1e4382f5094d0fb4fdd308ffbc10935458865 1e86040a05fc43ff99961152921bbc9a62584039657b0998b2879729c9f35228 74451c739e262992485778772cdacf4b517720f9a1fea00ad90330229fd04ee7 9131f2ab66c1a3f11970b75e62901dea206b7258408a46054c625af71967443a c26546b85900eb170da74efe3f96c9aade92604e586709e715ec1f3f0877b1a4 d047bb131952eaa79388023e3209315b0f1c0551fe58405f7d1e44009f3234b4 3d1a4218ad09c9e105ebd5fb9a6ee9d63db90d480adf971ec73f44cf17ecf049 4c4a43c7fe8d254b3210ddc348d24b8a86264ea54712965840f8f2bc342dfdd9 db907b43a90cd5c80ffba67366a196c0c049b0c82026eccf9f3640c95bd79a79 bf4cc25e8934f344f5bf53576e5381416b7a733d8807ae1900¶
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'c53b6dd79549f609f4ffafbe7ff38715e41612116e0dbfd3b07025e947b12af0', / nonce /
}
¶
Figure: Presentation Header (SU-ES256, CBOR)¶
When the appropriate proof is generated, the CPT is serialized into the following CBOR (in hex):¶
845846a3010106781d68747470733a2f2f726563697069656e742e6578616d70 6c652e636f6d075820c53b6dd79549f609f4ffafbe7ff38715e41612116e0dbf d3b07025e947b12af058cfa701010314057668747470733a2f2f697373756572 2e6578616d706c650687060418aa18ab18b318bb6b6167655f6f7665725f3231 08a401022001215820a4ee14679cbff0f7e6149e18ee140e1837e3561c168e8c 1a428b2342df73fbee225820731062252114dc35009b83762e6cd29d0b234396 612c1fbd15807eed30c387dd09a401022001215820475d3d6bf78f922cc93d00 4301e72381cb78fa6e90a621f4c2d2e1d7b41a1cb822582054632d591370ef9a ac8474d9b3963826fc005ae45cc67b8d821b6ec94d464c8b0a28891a0a382700 1a0a3c3d3f63446f65634a6179726a6179646f65406578616d706c652e6f7267 a601782331323334204d61696e2053742e0a416e79746f776e2c204341203132 3334350a555341026d31323334204d61696e2053742e0367416e79746f776e04 624341056539303231300663555341f5f6f6875840d0a168fe890e5f97ebe907 2f03800029d11ca33b9207466a3e9827d2edf5c7fa825f68e60e322539a92884 07582c519352f328cd9b60141353ef1dfd6ced2df25840680338bc860e854137 05e8cc2929cadd66398b70137a49a93b2e69a325dc64fc93626d6a54c9b35962 3dbe5f438e21b1e10ecf7cc7dabd946ceaf70efb791ad758402b6754416cee0e 0093260edf6746b7513e2fa9daa917a65bd1a5dc87f1604ab0742fc34e253b38 5a8e9b77489958e0ed2a0c1f2449a3c90b605a08e7d9e5519658404f67e9d36c 3de27f7d732cac9166d71e3dcaa2d248885dbcc2295516e1e4382f5094d0fb4f dd308ffbc109354588651e86040a05fc43ff99961152921bbc9a62584039657b 0998b2879729c9f3522874451c739e262992485778772cdacf4b517720f9a1fe a00ad90330229fd04ee79131f2ab66c1a3f11970b75e62901dea206b7258408a 46054c625af71967443ac26546b85900eb170da74efe3f96c9aade92604e5867 09e715ec1f3f0877b1a4d047bb131952eaa79388023e3209315b0f1c0551fe58 4070bbc8c4274964045514cb26d3438ef1c074d62bfc24139907b10ba3b76245 e7d18640918e4ad867bced8ad4587ef8406221b1b76d686bbddde866cc5b2b91 0e¶
Figure: Presented Form (SU-ES256, CBOR)¶
The following example uses the BBS algorithm.¶
This is the Issuer's stable private key in the JWK format:¶
{
"kty": "OKP",
"alg": "BBS",
"use": "proof",
"crv": "BLS12381G2",
"x": "rM3dIFoAophypNfAcVEKRxD6TeFbo0VyfnSK-6ktjnE9VwPcbq8h6IVCL6ehc
tQPBLu9KCHnCrRlWTaY2SK9wNzgRKu9Z1MgwuDKFalmZU_btbHtUT31x05AMv4
r3uK1",
"d": "5wwVrk1Az1HwsRNpk5Kmf3gCl3QYMFurXhrng7OGlTc"
}
There is no additional holder key necessary for presentation proofs.¶
For the following protected header and array of payloads:¶
{
"kid": "HjfcpyjuZQ-O8Ye2hQnNbT9RbbnrobptdnExR0DUjU8",
"alg": "BBS"
}
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.gDZYAj2OpbySSh6XiXjWaindasL34eE08q pKyZMDW4O8AfRUShMzPY-B-AnTJEfjMw3A-PhOh1URDxlPJggyOvCgz8icBULjZc0a2rI yxmw
For a presentation with the following Presentation Header:¶
{
"alg": "BBS",
"aud": "https://recipient.example.com",
"nonce": "wrmBRkKtXjQ"
}
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~~~.pclzS0-41PTTTy1udJKlWE6LLKgPM1KqC48w3HsF ZcVtxHDiVSHDzn72Kb4i_2q2jSY1syKRFutTvZ3-6Rw-U6aI95LOHRekAGlBus6gRlrcE MHAr7JJWXsZJ7_8wwnCsmLv8RrDqQ9Ignf7wsOCZ7z_dsqf3FlXqUWeEKRrFWjQABcBHF my-o2rauLdxA8cPYZXoRacpUMCMFp_QfUn_C_teh32IC2jBEdWDklRQcI_rDGOjefSH6V u7PyQKAhgWaN_oz2zYDN3-Wh21S9ljF-UDeeUaT9LirPh22OG3Xc7530n90fX2tf1w6nC S0w3XQps6fscbOi9lavt8Q0M6CIxVKs8Owso7DrsPp--B9NaXPNjkHPfSP0hmupWJT1JZ oh4Jw3XQH_o1O80BO_hNlGWwofEqFL_ELZreJMxJR_pIAOwgsAPhAjJlX4pHtyNM_F2cQ 4XxkQr6MMDJijGkoU_Fkc0amS9AO_DWr7vy8U
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": "artZdEJNwOokMjb9QYAok2F5rdVGIEW8kWT6CdWxPD4",
"y": "U1GzkINYTblBJba6Y3BbvqUHVyLK9IceYwPRiW_5e-o",
"d": "JhsPV_JouEIELEfpK1ZePNDDhGjcI3HutBer8WMWE0M"
}
This is the Issuer's ephemerally generated shared secret:¶
"ikGqvfSk3Q09ASBJNsXThsLqfktG2rNanEPfXrki7l0"
This is the Holder's presentation private key in the JWK format:¶
{
"kty": "EC",
"crv": "P-256",
"x": "R109a_ePkizJPQBDAecjgct4-m6QpiH0wtLh17QaHLg",
"y": "VGMtWRNw75qshHTZs5Y4JvwAWuRcxnuNghtuyU1GTIs",
"d": "eFR6wFUCw4hhMh5YRuhNt3yP5XIKyJBfrwDKeRKbey4"
}
For the following Header and array of payloads:¶
{
"alg": "MAC-H256",
"hpa": "ES256",
"typ": "JPT",
"iss": "https://issuer.example",
"claims": [
"iat",
"exp",
"family_name",
"given_name",
"email",
"address",
"age_over_21"
],
"hpk": {
"kty": "EC",
"crv": "P-256",
"use": "sign",
"x": "R109a_ePkizJPQBDAecjgct4-m6QpiH0wtLh17QaHLg",
"y": "VGMtWRNw75qshHTZs5Y4JvwAWuRcxnuNghtuyU1GTIs"
}
}
[
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
]
The issuer generates an array of derived keys, one per payload slot. This is done using the shared secret as the key and a binary value based on the payload slot index (from zero) as input to the HMAC operation.¶
This results in the following set of derived keys:¶
[ "JwCD4QFY7Xw-Kuvjb9yvlw6LiN_mn85TjFdvOREqeHE", "Av7eXbaqR0-yFmWGRpqmx5IqK_Zh-iS7eG9axdbQP9c", "_itTDgcyKi0aZU-YSCT_re5WuwgpERBST3sn6RfTr1c", "rspecnneekFWQIpFsRhjI4X4ThcxMoukn32gjbyR0bA", "SKeMYc1jxRKu5WJDhTjI2ezxRRFiDbrrnqPUsWc5Hmo", "NksrgKIqMD0q8XSoioRC-_EuxE-P_jHcMmViHm4e-EI", "cxp9wKmz4zexRN4TBH_somKcI1BgfKRY7rUYCD1DcuQ" ]
A MAC is generated for each payload using the corresponding derived payload key. This results in the following set of MAC values:¶
[ "PUZEcmLb575K97IisHl3mYv8ZbRlUUb_t8fj1e3RyIo", "679n34oirqTYT4nbWXYsbqITBIGI8pmfparWYTjfB9k", "QpswWlqhXb747lGHcyAsV5OsRoFZct_Ddjrou-LJQzw", "YRQSRXtyjHVSqNiwfoyxjr27wpHwMM5SbzM2p-zinv8", "qCUxbqpnFNU48IuwcjPGwW7XgaeJvd3cQ-yl9e5gEVs", "pqAgVwLSIpoCMaBHv9KH39q-ereUDFAXw_WULKNNegU", "QiKQDS68NSgnhfgWSabd8uNxixwz1W2L9Oh_9Pr2FEc" ]
The Issuer Header and payload MAC values are combined into a binary representation known as the Compact 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.¶
[ "91xzm-cZ9Gwr3QYe_opE9OAOsWPY6BfU26oT6sIeiNcfTpdKYHibDHrP2klgtEHX4p ALR5IOqpucOcRPSZ_MBQ", "a1sBT7R55agarkINBC_hKY01X9OuueRO9zWoBBwNUcI" ]
The final issued JWP in compact serialization is:¶
eyJhbGciOiJNQUMtSDI1NiIsImhwYSI6IkVTMjU2IiwidHlwIjoiSlBUIiwiaXNzIjoia HR0cHM6Ly9pc3N1ZXIuZXhhbXBsZSIsImNsYWltcyI6WyJpYXQiLCJleHAiLCJmYW1pbH lfbmFtZSIsImdpdmVuX25hbWUiLCJlbWFpbCIsImFkZHJlc3MiLCJhZ2Vfb3Zlcl8yMSJ dLCJocGsiOnsia3R5IjoiRUMiLCJjcnYiOiJQLTI1NiIsInVzZSI6InNpZ24iLCJ4Ijoi UjEwOWFfZVBraXpKUFFCREFlY2pnY3Q0LW02UXBpSDB3dExoMTdRYUhMZyIsInkiOiJWR 010V1JOdzc1cXNoSFRaczVZNEp2d0FXdVJjeG51TmdodHV5VTFHVElzIn19.MTcxNDUyM TYwMA~MTcxNzE5OTk5OQ~IkRvZSI~IkpheSI~ImpheWRvZUBleGFtcGxlLm9yZyI~eyJm b3JtYXR0ZWQiOiIxMjM0IE1haW4gU3QuXG5Bbnl0b3duLCBDQSAxMjM0NVxuVVNBIiwic 3RyZWV0X2FkZHJlc3MiOiIxMjM0IE1haW4gU3QuIiwibG9jYWxpdHkiOiJBbnl0b3duIi wicmVnaW9uIjoiQ0EiLCJwb3N0YWxfY29kZSI6MTIzNDUsImNvdW50cnkiOiJVU0EifQ~ dHJ1ZQ.91xzm-cZ9Gwr3QYe_opE9OAOsWPY6BfU26oT6sIeiNcfTpdKYHibDHrP2klgtE HX4pALR5IOqpucOcRPSZ_MBQ~a1sBT7R55agarkINBC_hKY01X9OuueRO9zWoBBwNUcI
Next, we show the presentation of the JWP with selective disclosure.¶
For presentation with the following Presentation Header:¶
{
"alg": "MAC-H256",
"aud": "https://recipient.example.com",
"nonce": "xTtt15VJ9gn0_6--f_OHFeQWEhFuDb_TsHAl6UexKvA"
}
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:¶
[ "91xzm-cZ9Gwr3QYe_opE9OAOsWPY6BfU26oT6sIeiNcfTpdKYHibDHrP2klgtEHX4p ALR5IOqpucOcRPSZ_MBQ", "JwCD4QFY7Xw-Kuvjb9yvlw6LiN_mn85TjFdvOREqeHE", "Av7eXbaqR0-yFmWGRpqmx5IqK_Zh-iS7eG9axdbQP9c", "_itTDgcyKi0aZU-YSCT_re5WuwgpERBST3sn6RfTr1c", "rspecnneekFWQIpFsRhjI4X4ThcxMoukn32gjbyR0bA", "qCUxbqpnFNU48IuwcjPGwW7XgaeJvd3cQ-yl9e5gEVs", "pqAgVwLSIpoCMaBHv9KH39q-ereUDFAXw_WULKNNegU", "QiKQDS68NSgnhfgWSabd8uNxixwz1W2L9Oh_9Pr2FEc", "J0KnV1cbP9OZEQ5HjHFl5D3XvCbblPCCm57Kg2Y5p8V-nTlryg_Rm69hnzaefF48gT CnP0qzJ91QDUMYw-QGZg" ]
The final presented JWP in compact serialization is:¶
eyJhbGciOiJNQUMtSDI1NiIsImF1ZCI6Imh0dHBzOi8vcmVjaXBpZW50LmV4YW1wbGUuY 29tIiwibm9uY2UiOiJ4VHR0MTVWSjlnbjBfNi0tZl9PSEZlUVdFaEZ1RGJfVHNIQWw2VW V4S3ZBIn0.eyJhbGciOiJNQUMtSDI1NiIsImhwYSI6IkVTMjU2IiwidHlwIjoiSlBUIiw iaXNzIjoiaHR0cHM6Ly9pc3N1ZXIuZXhhbXBsZSIsImNsYWltcyI6WyJpYXQiLCJleHAi LCJmYW1pbHlfbmFtZSIsImdpdmVuX25hbWUiLCJlbWFpbCIsImFkZHJlc3MiLCJhZ2Vfb 3Zlcl8yMSJdLCJocGsiOnsia3R5IjoiRUMiLCJjcnYiOiJQLTI1NiIsInVzZSI6InNpZ2 4iLCJ4IjoiUjEwOWFfZVBraXpKUFFCREFlY2pnY3Q0LW02UXBpSDB3dExoMTdRYUhMZyI sInkiOiJWR010V1JOdzc1cXNoSFRaczVZNEp2d0FXdVJjeG51TmdodHV5VTFHVElzIn19 .MTcxNDUyMTYwMA~MTcxNzE5OTk5OQ~IkRvZSI~IkpheSI~~~.91xzm-cZ9Gwr3QYe_op E9OAOsWPY6BfU26oT6sIeiNcfTpdKYHibDHrP2klgtEHX4pALR5IOqpucOcRPSZ_MBQ~J wCD4QFY7Xw-Kuvjb9yvlw6LiN_mn85TjFdvOREqeHE~Av7eXbaqR0-yFmWGRpqmx5IqK_ Zh-iS7eG9axdbQP9c~_itTDgcyKi0aZU-YSCT_re5WuwgpERBST3sn6RfTr1c~rspecnn eekFWQIpFsRhjI4X4ThcxMoukn32gjbyR0bA~qCUxbqpnFNU48IuwcjPGwW7XgaeJvd3c Q-yl9e5gEVs~pqAgVwLSIpoCMaBHv9KH39q-ereUDFAXw_WULKNNegU~QiKQDS68NSgnh fgWSabd8uNxixwz1W2L9Oh_9Pr2FEc~J0KnV1cbP9OZEQ5HjHFl5D3XvCbblPCCm57Kg2 Y5p8V-nTlryg_Rm69hnzaefF48gTCnP0qzJ91QDUMYw-QGZg
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 .¶
[[ To be removed from the final specification ]] -11¶
-10¶
-09¶
-08¶
-07¶
proof_key and presentation_key
names¶
proof_jwk to proof_key and presentation_jwk to
presentation_key to better represent that the key may be JSON or
CBOR-formatted.¶
proof_key and presentation_key to JWP where
they are defined. Consolidated usage, purpose, and requirements from
algorithm usage under these definitions.¶
BBS-PROOF into BBS¶
-06¶
presentation_header.¶
pjwk to presentation_jwk¶
-05¶
-04¶
BBS-DRAFT-5 to BBS, and from
BBS-PROOF-DRAFT-5 to BBS-PROOF¶
BBS_BLS12381G1_XMD:SHA-256_SSWU_RO_¶
-03¶
-02¶
BBS-DRAFT-3 and BBS-PROOF-DRAFT-3 algorithms based on
draft-irtf-cfrg-bbs-signatures-03.¶
BBS-X algorithm based on a particular implementation of
earlier drafts.¶
-01¶
issuer_header and presentation_header¶
-00¶