JSON Proof Algorithms
draft-ietf-jose-json-proof-algorithms-07
| Document | Type | Active Internet-Draft (jose WG) | |
|---|---|---|---|
| Authors | Michael B. Jones , David Waite , Jeremie Miller | ||
| Last updated | 2024-10-21 | ||
| Replaces | draft-jmiller-jose-json-proof-algorithms | ||
| RFC stream | Internet Engineering Task Force (IETF) | ||
| Intended RFC status | (None) | ||
| Formats | |||
| Additional resources | Mailing list discussion | ||
| Stream | WG state | WG Document | |
| Document shepherd | (None) | ||
| IESG | IESG state | I-D Exists | |
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| Send notices to | (None) |
draft-ietf-jose-json-proof-algorithms-07
jose M. Jones
Internet-Draft Self-Issued Consulting
Intended status: Standards Track D. Waite
Expires: 24 April 2025 J. Miller
Ping Identity
21 October 2024
JSON Proof Algorithms
draft-ietf-jose-json-proof-algorithms-07
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 24 April 2025.
Copyright Notice
Copyright (c) 2024 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents (https://trustee.ietf.org/
license-info) in effect on the date of publication of this document.
Please review these documents carefully, as they describe your rights
and restrictions with respect to this document. Code Components
extracted from this document must include Revised BSD License text as
described in Section 4.e of the Trust Legal Provisions and are
provided without warranty as described in the Revised BSD License.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Conventions and Definitions . . . . . . . . . . . . . . . . . 3
3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
4. Background . . . . . . . . . . . . . . . . . . . . . . . . . 4
5. Algorithm Basics . . . . . . . . . . . . . . . . . . . . . . 4
5.1. Issue . . . . . . . . . . . . . . . . . . . . . . . . . . 4
5.2. Confirm . . . . . . . . . . . . . . . . . . . . . . . . . 5
5.3. Present . . . . . . . . . . . . . . . . . . . . . . . . . 5
5.4. Verify . . . . . . . . . . . . . . . . . . . . . . . . . 5
6. Algorithm Specifications . . . . . . . . . . . . . . . . . . 6
6.1. Single Use . . . . . . . . . . . . . . . . . . . . . . . 6
6.1.1. JWS Algorithm . . . . . . . . . . . . . . . . . . . . 6
6.1.2. Holder Setup . . . . . . . . . . . . . . . . . . . . 6
6.1.3. Issuer Setup . . . . . . . . . . . . . . . . . . . . 7
6.1.4. Signing payloads . . . . . . . . . . . . . . . . . . 7
6.1.5. Issuer Protected Header . . . . . . . . . . . . . . . 7
6.1.6. Payloads . . . . . . . . . . . . . . . . . . . . . . 7
6.1.7. Proof . . . . . . . . . . . . . . . . . . . . . . . . 7
6.1.8. Presentation Protected Header . . . . . . . . . . . . 7
6.1.9. Presentation . . . . . . . . . . . . . . . . . . . . 8
6.1.10. Verification . . . . . . . . . . . . . . . . . . . . 9
6.1.11. JPA Registration . . . . . . . . . . . . . . . . . . 9
6.2. BBS . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
6.2.1. JPA Algorithms . . . . . . . . . . . . . . . . . . . 9
6.2.2. Key Format . . . . . . . . . . . . . . . . . . . . . 9
6.2.3. Issuance . . . . . . . . . . . . . . . . . . . . . . 10
6.2.4. Issuance Proof Verification . . . . . . . . . . . . . 10
6.2.5. Presentation . . . . . . . . . . . . . . . . . . . . 10
6.2.6. Presentation Verification . . . . . . . . . . . . . . 11
6.3. Message Authentication Code . . . . . . . . . . . . . . . 11
6.3.1. Holder Setup . . . . . . . . . . . . . . . . . . . . 11
6.3.2. Issuer Setup . . . . . . . . . . . . . . . . . . . . 12
6.3.3. Combined MAC Representation . . . . . . . . . . . . . 12
6.3.4. Issuer Proof . . . . . . . . . . . . . . . . . . . . 12
6.3.5. Presentation Protected Header . . . . . . . . . . . . 13
6.3.6. Presentation Proof . . . . . . . . . . . . . . . . . 13
6.3.7. Verification of the Presentation Proof . . . . . . . 13
6.3.8. JPA Registration . . . . . . . . . . . . . . . . . . 14
7. Security Considerations . . . . . . . . . . . . . . . . . . . 14
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14
8.1. JSON Web Proof Algorithms Registry . . . . . . . . . . . 15
8.1.1. Registration Template . . . . . . . . . . . . . . . . 16
8.1.2. Initial Registry Contents . . . . . . . . . . . . . . 17
8.1.2.1. Single-Use JWP using ES256 Algorithm . . . . . . 17
8.1.2.2. Single-Use JWP using ES384 Algorithm . . . . . . 17
8.1.2.3. Single-Use JWP using ES512 Algorithm . . . . . . 17
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8.1.2.4. BBS using SHA-256 Algorithm . . . . . . . . . . . 18
8.1.2.5. MAC-H256 Algorithm . . . . . . . . . . . . . . . 18
8.1.2.6. MAC-H384 Algorithm . . . . . . . . . . . . . . . 18
8.1.2.7. MAC-H512 Algorithm . . . . . . . . . . . . . . . 18
8.1.2.8. MAC-K25519 Algorithm . . . . . . . . . . . . . . 19
8.1.2.9. MAC-K448 Algorithm . . . . . . . . . . . . . . . 19
8.1.2.10. MAC-H256K Algorithm . . . . . . . . . . . . . . . 19
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 20
9.1. Normative References . . . . . . . . . . . . . . . . . . 20
9.2. Informative References . . . . . . . . . . . . . . . . . 20
Appendix A. Example JWPs . . . . . . . . . . . . . . . . . . . . 21
A.1. Example Single-Use JWP . . . . . . . . . . . . . . . . . 21
A.2. Example BBS JWP . . . . . . . . . . . . . . . . . . . . . 29
A.3. Example MAC JWP . . . . . . . . . . . . . . . . . . . . . 32
Appendix B. Acknowledgements . . . . . . . . . . . . . . . . . . 39
Appendix C. Document History . . . . . . . . . . . . . . . . . . 39
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 41
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.
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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.
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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.
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If the presented proof contains any assertions about the hidden
payloads, the algorithm MUST also verify all of those assertions. It
MAY support additional options, such as those sent to the holder to
generate the presentation.
If given an issued JWP for verification, the algorithm MUST return an
error.
6. Algorithm Specifications
This section defines how to use specific algorithms for JWPs.
6.1. Single Use
The Single Use (SU) algorithm is based on composing multiple
traditional asymmetric signatures into a single JWP proof. It
enables a very simple form of selective disclosure without requiring
any advanced cryptographic techniques.
It does not support unlinkability if the same JWP is presented
multiple times, therefore when privacy is required the holder will
need to interact with the issuer again to receive new single-use JWPs
(dynamically or in batches).
6.1.1. JWS Algorithm
The Single Use algorithm is based on using multiple signatures to
cover the individual payloads, all of which are generated with the
same Asymmetric JSON Web Algorithm (JWA). The internal signing
algorithm to use is part of the registration for a new Single Use
algorithm identifier.
The chosen JWA MUST be an asymmetric signing algorithm so that each
signature can be verified without sharing any private values between
the parties. This ensures that the verifier cannot brute force any
non-disclosed payloads based only on their disclosed individual
signatures.
6.1.2. Holder Setup
In order to support the protection of a presentation by a holder to a
verifier, the holder MUST use a Presentation Key during the issuance
and the presentation of every Single Use JWP. This Presentation Key
MUST be generated and used for only one JWP.
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The issuer MUST verify that the holder has possession of this key.
The holder-issuer communication to exchange this information is out
of scope of this specification, but can be accomplished by the holder
using this key to generate a JWS that signs a value the issuer can
verify as unique.
6.1.3. Issuer Setup
To create a Single Use JWP, the issuer first generates a unique
Ephemeral Key using the selected internal algorithm. This key-pair
will be used to sign each of the payloads of a single JWP and then
discarded.
6.1.4. Signing payloads
Each individual payload is signed using the selected internal
algorithm using the Ephemeral Key.
6.1.5. Issuer Protected Header
The issuer's Ephemeral Key MUST be included in the issuer protected
header via the Proof Key header parameter.
The holder's Presentation Key MUST be included in issuer protected
header via the Presentation Key header parameter.
The issuer protected header is signed using the given JWA and the
issuer's Stable Key.
6.1.6. Payloads
Each JWP payload is processed in order and signed using the given JWA
using the issuer's Ephemeral Key.
6.1.7. Proof
The proof value is an octet string array. The first entry is the
octet string of the issuer protected header signature, with an
additional entry for each payload signature.
6.1.8. Presentation Protected Header
To generate a new presentation, the holder first creates a
presentation protected header that is specific to the verifier being
presented to. This header MUST contain a parameter that both the
holder and verifier trust as being unique and non-replayable. Use of
the nonce header parameter is RECOMMENDED for this purpose.
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This specification registers the nonce header parameter for the
presentation protected header that contains a string value either
generated by the verifier or derived from values provided by the
verifier. When present, the verifier MUST ensure the nonce value
matches during verification.
The presentation protected header MAY contain other header parameters
that are either provided by the verifier or by the holder. These
presentation header parameters SHOULD NOT contain values that are
common across multiple presentations and SHOULD be unique to a single
presentation and verifier.
6.1.9. Presentation
| Editor's Note: The current definition here is incomplete, the
| holder's signature needs to also incorporate the presented proof.
The holder derives a new proof as part of presentation. The
presented proof value will always contain the issuer's Stable Key
signature for the issuer protected header as the first element.
The second element of the presented proof is the holder's signature
of the presentation protected header using the holder's presentation
key. This signature is constructed using the same algorithm
described in generating the issuer's signature over the issuer
protected header. Signing only the presentation header with the
Presentation Key is sufficient to protect the entire presentation
since that key is private to the holder and only the contents of the
presentation header are used for replay prevention.
For each payload which is to be disclosed, the corresponding payload
signature (from the issued JWP) is included in the proof. If a
payload is omitted from the presented JWP, the signature value will
NOT be includeed, and the presentation proof will have one less part.
For example, if the second and fifth of five payloads are not
disclosed, then the holder's derived proof would consist of the
issuer's signature over the issuer protected header, the holder's
signature over the holder's protected header, the ephemeral key
signature over the first, third and fourth payloads.
Since the individual signatures in the proof value are unique and
remain unchanged across multiple presentations, a Single Use JWP
SHOULD only be presented a single time to each verifier in order for
the holder to remain unlinkable across multiple presentations.
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6.1.10. Verification
The verifier MUST verify the issuer protected header octets against
the first part in the proof using the issuer's Stable Key. It MUST
also verify the presentation protected header octets against the
second part in the proof value using the holder's Presentation Key,
as provided in the Presentation Key header parameter.
With the headers verified, the Proof Key header parameter can then be
used to verify each of the disclosed payload signatures.
6.1.11. JPA Registration
The proposed JWP alg value is of the format "SU-" appended with the
relevant JWS alg value for the chosen public and ephemeral key-pair
algorithm, for example "SU-ES256".
6.2. BBS
The BBS Signature Scheme [I-D.irtf-cfrg-bbs-signatures] is under
active development within the CRFG.
This algorithm supports both selective disclosure and unlinkability,
enabling the holder to generate multiple presentations from one
issued JWP without a verifier being able to correlate those
presentations together based on the proof.
6.2.1. JPA Algorithms
The BBS algorithm corresponds to a ciphersuite identifier of
BBS_BLS12381G1_XMD:SHA-256_SSWU_RO_.
6.2.2. Key Format
The key used for the BBS algorithm is an elliptic curve-based key
pair, specifically against the G_2 subgroup of a pairing friendly
curve. Additional details on key generation can be found in
Section 3.4. The JWK and Cose Key Object representations of the key
are detailed in [I-D.ietf-cose-bls-key-representations].
There is no additional holder presentation key necessary for
presentation proofs.
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6.2.3. Issuance
Issuance is performed using the Sign operation from Section 3.5.1 of
[I-D.irtf-cfrg-bbs-signatures]. This operation utilizes the issuer's
BLS12-381 G2 key pair as SK and PK, along with desired protected
header and payloads as the octets header and the octets array
messages.
The octets resulting from this operation form a single octet string
in the issuance proof array, to be used along with the protected
header and payloads to serialize the JWP.
6.2.4. Issuance Proof Verification
Holder verification of the signature on issuance form is performed
using the Verify operation from Section 3.5.2 of
[I-D.irtf-cfrg-bbs-signatures].
This operation utilizes the issuer's public key as PK, the proof as
signature, the protected header octets as header and the array of
payload octets as messages.
6.2.5. Presentation
Derivation of a presentation is done by the holder using the ProofGen
operation from Section 3.5.3 of [I-D.irtf-cfrg-bbs-signatures].
This operation utilizes the issuer's public key as PK, the issuer
protected header as header, the issuance proof as signature, the
issuance payloads as messages, and the holder's presentation
protected header as ph.
The operation also takes a vector of indexes into messages,
describing which payloads the holder wishes to disclose. All
payloads are required for proof generation, but only these indicated
payloads will be required to be disclosed for later proof
verification.
The output of this operation is the presentation proof, as a single
octet string.
Presentation serialization leverages the two protected headers and
presentation proof, along with the disclosed payloads. Non-disclosed
payloads are represented with the absent value of null in JSON
serialization and a zero-length string in compact serialization.
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6.2.6. Presentation Verification
Verification of a presentation is done by the verifier using the
ProofVerify operation from Section 3.5.4.
This operation utilizes the issuer's public key as PK, the issuer
protected header as header, the issuance proof as signature, the
holder's presentation protected header as ph, and the payloads as
disclosed_messages.
In addition, the disclosed_indexes scalar array is calculated from
the payloads provided. Values disclosed in the presented payloads
have a zero-based index in this array, while the indices of absent
payloads are omitted.
6.3. Message Authentication Code
The Message Authentication Code (MAC) JPA uses a MAC to both generate
ephemeral keys and compute authentication codes to protect the issuer
header and each payload individually.
Like the the Single Use algorithm family, it also does not support
unlinkability if the same JWP is presented multiple times. and
requires an individually issued JWP for each presentation in order to
fully protect privacy. When compared to the JWS approach, using a
MAC requires less computation but can result in potentially larger
presentation proof values.
The design is intentionally minimal and only involves using a single
standardized MAC method instead of a mix of MAC/hash methods or a
custom hash-based construct. It is able to use any published
cryptographic MAC method such as HMAC [RFC2104] or KMAC
(https://nvlpubs.nist.gov/nistpubs/SpecialPublications/
NIST.SP.800-185.pdf). It uses traditional public-key based
signatures to verify the authenticity of the issuer and holder.
6.3.1. Holder Setup
Prior to the issuer creating a new JWP, the issuer MUST have a
presentation public key provided by the holder.
The holder's presentation key MUST be included in the issuer's
protected header using the Presentation Key header parameter.
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6.3.2. Issuer Setup
To use the MAC algorithm, the issuer must have a stable public key
pair to perform signing. To start the issuance process, a single
32-byte random Shared Secret must first be generated. This value
will be shared privately to the holder as part of the issuer's JWP
proof value.
The Shared Secret is used by both the issuer and holder as the MAC
method's key to generate a new set of unique ephemeral keys. These
keys are then used as the input to generate a MAC that protects each
payload.
6.3.3. Combined MAC Representation
The combined MAC representation is a single octet string representing
the MAC values of the issuer protected header, along with each
payload provided by the issuer. This representation is signed by the
issuer, but not shared - parties will recreate this octet string and
verify the signature to verify the integrity of supplied issuer
protected header and the integrity of any disclosed payloads.
The issuer protected header is included in this value as a MAC
created using the fixed key "issuer_header" in UTF-8 encoded octets.
The value is the issuer header JSON as a UTF-8 encoded octet string.
A unique key is generated for each payload using a MAC, with the
Shared Secret as the key and a value of "payload_X" as UTF-8 encoded
octets, where "X" is replaced by the zero-based array index of the
payload, for example "payload_0", "payload_1", etc.
Each payload then itself has a corresponding MAC, using the above
per-payload key and the payload octet string.
The combined MAC representation is the octet string formed by the the
concatentation of the issuer protected header MAC output, along with
each payload MAC output.
6.3.4. Issuer Proof
The issuer proof consists of two octet strings.
The first octet string is the issuer signature over the combined MAC
representation. The issuer signs the JWS using its stable public
key, and a fixed header containing the alg associated with signing
algorithm in use.
jws_header = '{"alg":"ES256"}'
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The signature value of the JWS is extracted and base64url-decoded
into an octet string.
The second octet string is the Shared Secret used to generate the
per-payload keys for the combined representation.
6.3.5. Presentation Protected Header
See the JWS Presentation Protected Header (#presentation-protected-
header) section.
6.3.6. Presentation Proof
| Editor's Note: The current definition here is incomplete, the
| holder's signature needs to also incorporate the presented proof.
The first value in the presentation proof is the presentation
signature. This is a signature over the presentation protected
header, using the key specified by the Presentation Key header
parameter in the issuer protected header.
The second value is the issuer signature over the Combined MAC
Representation provided with the issued form.
The remaining values are used by the verifier to reconstruct the
combined MAC representation without access to the Shared Secret.
There is one value corresponding to each payload, whether it has been
disclosed or not.
If a payload is disclosed, the unique per-payload key derived from
the shared secret is used as the payload's entry in the proof array.
If a payload is not disclosed, the payload's MAC in the combined MAC
representation is used as the payload's entry in the proof array.
6.3.7. Verification of the Presentation Proof
The verifier must recreate the Combined MAC Representation from the
presentation proof to verify integrity over the disclosed
information.
The issuer protected header MAC is recreated using the same mechanism
described above.
For each payload in the presentation:
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* If the payload is disclosed, then the presentation proof contains
the unique per-payload key. The corresponding payload MAC can be
computed by performing the MAC operation with this key and the
corresponding payload.
* If the payload is not disclosed, then the presentation proof
contains the payload MAC, which can be used directly
The concatenation of the octets of the issuer protected header MAC
and each payload MAC forms the Combined MAC Representation. The
issuer signature in the proof is then verified by converting these
values to a JWS as described above, and verifying that JWS.
6.3.8. JPA Registration
Proposed JWP alg value is of the format "MAC-" appended with a unique
identifier for the set of MAC and signing algorithms used. Below are
the initial registrations:
* MAC-H256 uses HMAC SHA-256 as the MAC and ECDSA using P-256 and
SHA-256 for the signatures
* MAC-H384 uses HMAC SHA-384 as the MAC and ECDSA using P-384 and
SHA-384 for the signatures
* MAC-H512 uses HMAC SHA-512 as the MAC and ECDSA using P-521 and
SHA-512 for the signatures
* MAC-K25519 uses KMAC SHAKE128 as the MAC and EdDSA using
Curve25519 for the signatures
* MAC-K448 uses KMAC SHAKE256 as the MAC and EdDSA using Curve448
for the signatures
* MAC-H256K uses HMAC SHA-256 as the MAC and ECDSA using secp256k1
and SHA-256 for the signatures
7. Security Considerations
| Editor's Note: This will follow once the algorithms defined here
| have become more stable.
* Data minimization of the proof value
* Unlinkability of the protected header contents
8. IANA Considerations
The following registration procedure is used for all the registries
established by this specification.
Values are registered on a Specification Required [RFC5226] basis
after a three-week review period on the [email protected]
mailing list, on the advice of one or more Designated Experts.
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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
[email protected] 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
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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.
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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
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* 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 6.2.1 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 6.3.8 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 6.3.8 of this specification
* Algorithm Analysis Documents(s): n/a
8.1.2.7. MAC-H512 Algorithm
* Algorithm Name: MAC-H512
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* 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 6.3.8 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 6.3.8 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 6.3.8 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 6.3.8 of this specification
* Algorithm Analysis Documents(s): n/a
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9. References
9.1. Normative References
[I-D.ietf-jose-json-web-proof]
Miller, J., Waite, D., and M. B. Jones, "JSON Web Proof",
Work in Progress, Internet-Draft, draft-ietf-jose-json-
web-proof-06, 16 September 2024,
<https://datatracker.ietf.org/doc/html/draft-ietf-jose-
json-web-proof-06>.
[I-D.irtf-cfrg-bbs-signatures]
Looker, T., Kalos, V., Whitehead, A., and M. Lodder, "The
BBS Signature Scheme", Work in Progress, Internet-Draft,
draft-irtf-cfrg-bbs-signatures-07, 23 September 2024,
<https://datatracker.ietf.org/doc/html/draft-irtf-cfrg-
bbs-signatures-07>.
9.2. Informative References
[I-D.ietf-cose-bls-key-representations]
Looker, T. and M. B. Jones, "Barreto-Lynn-Scott Elliptic
Curve Key Representations for JOSE and COSE", Work in
Progress, Internet-Draft, draft-ietf-cose-bls-key-
representations-05, 17 March 2024,
<https://datatracker.ietf.org/doc/html/draft-ietf-cose-
bls-key-representations-05>.
[RFC2104] Krawczyk, H., Bellare, M., and R. Canetti, "HMAC: Keyed-
Hashing for Message Authentication", RFC 2104,
DOI 10.17487/RFC2104, February 1997,
<https://www.rfc-editor.org/info/rfc2104>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", RFC 5226,
DOI 10.17487/RFC5226, May 2008,
<https://www.rfc-editor.org/info/rfc5226>.
[RFC7515] Jones, M., Bradley, J., and N. Sakimura, "JSON Web
Signature (JWS)", RFC 7515, DOI 10.17487/RFC7515, May
2015, <https://www.rfc-editor.org/info/rfc7515>.
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[RFC7518] Jones, M., "JSON Web Algorithms (JWA)", RFC 7518,
DOI 10.17487/RFC7518, May 2015,
<https://www.rfc-editor.org/info/rfc7518>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[VC-DATA-MODEL-2.0]
Sporny, M., Jr, T. T., Herman, I., Jones, M. B., and G.
Cohen, "Verifiable Credentials Data Model 2.0", 27
December 2023, <https://www.w3.org/TR/vc-data-model-2.0>.
Appendix A. Example JWPs
The following examples use algorithms defined in JSON Proof
Algorithms and also contain the keys used, so that implementations
can validate these samples.
A.1. Example Single-Use JWP
This example uses the Single-Use Algorithm as defined in JSON Proof
Algorithms to create a JSON Proof Token. It demonstrates how to
apply selective disclosure using an array of traditional JWS-based
signatures. Unlinkability is only achieved by using each JWP one
time, as multiple uses are inherently linkable via the traditional
ECDSA signature embedded in the proof.
To begin, we need two asymmetric keys for Single Use: one that
represents the JPT Issuer's stable key and the other is an ephemeral
key generated by the Issuer just for this JWP.
This is the Issuer's stable private key used in this example in the
JWK format:
{
"kty": "EC",
"crv": "P-256",
"x": "rljcEFI0caNXx29jNkyLXtbPti5qHkokC6PWy9XYAeM",
"y": "I6OlSc34yeKQMvXvq4aV6M12ESAK9RkdArMIeAWi70M",
"d": "xa0e8RpopMldqZCT7g9-2gDlWM1PrHz1N-qoQOcXU6U"
}
Figure 1: Issuer Private Key (es256)
This is the ephemeral private key used in this example in the JWK
format:
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{
"kty": "EC",
"crv": "P-256",
"x": "UUITdYuYGDeP97Tkk08qfRbGuhoR3LemQCRrWzlS-Do",
"y": "IJxVmTxCIVeNyCmk6sH8CeO7zRrJ1k6HQEPSXKY6H3c",
"d": "et_fHv5CfgzYakpzHibmX2U75oI_JxEpBSvzc5PoDPQ"
}
Figure 2: Issuer Ephemeral Private Key (es256)
This is the Holder's presentation private key used in this example in
the JWK format:
{
"kty": "EC",
"crv": "P-256",
"x": "y9wnI7zYYrkcXpd5j9O3qiRDMxmhPdNfbPzHtLIL_H0",
"y": "A2AJXiAYrlSGfwONgffXWaNnTXx-MXISPFRiwXMpEkg",
"d": "ZJco2u6h3y4g7M5otiVhTbfAEUSDMTkiSk76URi045c"
}
Figure 3: Holder Presentation Private Key
The JWP Protected Header declares that the data structure is a JPT
and the JWP Proof Input is secured using the Single-Use ECDSA
algorithm with the P-256 curve and SHA-256 digest. It also includes
the ephemeral public key, the Holder's presentation public key and
list of claims used for this JPT.
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{
"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": "UUITdYuYGDeP97Tkk08qfRbGuhoR3LemQCRrWzlS-Do",
"y": "IJxVmTxCIVeNyCmk6sH8CeO7zRrJ1k6HQEPSXKY6H3c",
"d": "et_fHv5CfgzYakpzHibmX2U75oI_JxEpBSvzc5PoDPQ"
},
"presentation_key": {
"kty": "EC",
"crv": "P-256",
"x": "y9wnI7zYYrkcXpd5j9O3qiRDMxmhPdNfbPzHtLIL_H0",
"y": "A2AJXiAYrlSGfwONgffXWaNnTXx-MXISPFRiwXMpEkg",
"d": "ZJco2u6h3y4g7M5otiVhTbfAEUSDMTkiSk76URi045c"
}
}
Figure 4: Issuer Protected header (es256)
The JWP Protected Header JSON is serialized (without the above
whitespace added for readability) and uses UTF-8 encoding to convert
into an octet string. This gives: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Figure 5: Encoded Issuer Protected Header (es256, base64url-encoded)
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The Single Use algorithm utilizes multiple individual JWS Signatures.
Each signature value is generated by creating a JWS with a single
Protected Header with the associated alg value. In this example, the
fixed header used for each JWS is the serialized JSON Object
{"alg":"ES256"}. This protected header will be used to generate a
signature over each corresponding payload in the JWP. The
corresponding octet value in the proof is the octet string
(base64url-decoded) value of the signature.
The final proof value from the Issuer is an array with the octets of
the header signature, followed by entries for each payload signature.
The resulting JSON serialized JPT using the above examples is:
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{
"issuer": "eyJhbGciOiJTVS1FUzI1NiIsInR5cCI6IkpQVCIsImlzcyI6Imh0dHBz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",
"payloads": [
"MTcxNDUyMTYwMA",
"MTcxNzE5OTk5OQ",
"IkRvZSI",
"IkpheSI",
"ImpheWRvZUBleGFtcGxlLm9yZyI",
"eyJmb3JtYXR0ZWQiOiIxMjM0IE1haW4gU3QuXG5Bbnl0b3duLCBDQSAxMjM0NVxu
VVNBIiwic3RyZWV0X2FkZHJlc3MiOiIxMjM0IE1haW4gU3QuIiwibG9jYWxpdH
kiOiJBbnl0b3duIiwicmVnaW9uIjoiQ0EiLCJwb3N0YWxfY29kZSI6MTIzNDUs
ImNvdW50cnkiOiJVU0EifQ",
"dHJ1ZQ"
],
"proof": [
"37RhnitI5rt3skZ9oRDpeGyxSynhvPxbhxe2_NDm4tQ8audwHH4nV7Qt7wN_vfNv
HZ_P3gkiNdrElSMBZcu1Xg",
"IIpR1uezrjhTgnVU4LY5KIdZOjayjRHFP6-ULHDv2ctMVSFTprkTpjvUwkgk1T2v
q6IHO5ptkISaglrWLur8vQ",
"sBFFXFVZKVuIoB2SiuyDCBSnC6Zkk10nWfsOn-I1CKAI0NC2QBxloc7gzxG4m4EN
SMKKpa9FKvyOtoBZi4YK2Q",
"svvidNTTnZU7D5Kze_SKBRhN3vJiUzs1bPQlK8_PIhqQrFhpKRiOI89Qqz6zqGdi
a1s8IfMYwNPoYJYIlYeNlw",
"yecfskC44VxcKWgZvUTWOXtp4EZ3kVYKAq1f_vCdPsxRkOrEsx7ADTXQtB0ksDhu
sEbwrqNP8ouNMSaHtKNucw",
"nMQ5lVAojfiJhzYYdKvL7kW35gXuquxrwAwntdjoNzfn7h6do63seUuSx8FUckdK
pDGODhWSCQtM6S38oc4Rcw",
"VXbFtQwnhCRB0jxdVQe1YDahf2fXAsiIvErjzTGbVFw_T_sjN2GZ9uLAyjzyjjXW
RwBWpZVs8-evVrvWbnPoBA",
"TP3ATOtrSCGq1Ej_aLMEkFvgnlacq4S5Kx0an3_45jNE9ZrAg9Dvm2hEtRQwYF_u
EBIL17atsb2jo7y6tLthVQ"
]
}
Figure 6: Issued JWP in JSON Serialization (es256)
The compact serialization of the same JPT is:
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eyJhbGciOiJTVS1FUzI1NiIsInR5cCI6IkpQVCIsImlzcyI6Imh0dHBzOi8vaXNzdWVyL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.MTcxNDUyMTYwMA~MTcxNzE5OTk5OQ~IkRvZSI~IkpheSI~ImpheWRv
ZUBleGFtcGxlLm9yZyI~eyJmb3JtYXR0ZWQiOiIxMjM0IE1haW4gU3QuXG5Bbnl0b3duL
CBDQSAxMjM0NVxuVVNBIiwic3RyZWV0X2FkZHJlc3MiOiIxMjM0IE1haW4gU3QuIiwibG
9jYWxpdHkiOiJBbnl0b3duIiwicmVnaW9uIjoiQ0EiLCJwb3N0YWxfY29kZSI6MTIzNDU
sImNvdW50cnkiOiJVU0EifQ~dHJ1ZQ.37RhnitI5rt3skZ9oRDpeGyxSynhvPxbhxe2_N
Dm4tQ8audwHH4nV7Qt7wN_vfNvHZ_P3gkiNdrElSMBZcu1Xg~IIpR1uezrjhTgnVU4LY5
KIdZOjayjRHFP6-ULHDv2ctMVSFTprkTpjvUwkgk1T2vq6IHO5ptkISaglrWLur8vQ~sB
FFXFVZKVuIoB2SiuyDCBSnC6Zkk10nWfsOn-I1CKAI0NC2QBxloc7gzxG4m4ENSMKKpa9
FKvyOtoBZi4YK2Q~svvidNTTnZU7D5Kze_SKBRhN3vJiUzs1bPQlK8_PIhqQrFhpKRiOI
89Qqz6zqGdia1s8IfMYwNPoYJYIlYeNlw~yecfskC44VxcKWgZvUTWOXtp4EZ3kVYKAq1
f_vCdPsxRkOrEsx7ADTXQtB0ksDhusEbwrqNP8ouNMSaHtKNucw~nMQ5lVAojfiJhzYYd
KvL7kW35gXuquxrwAwntdjoNzfn7h6do63seUuSx8FUckdKpDGODhWSCQtM6S38oc4Rcw
~VXbFtQwnhCRB0jxdVQe1YDahf2fXAsiIvErjzTGbVFw_T_sjN2GZ9uLAyjzyjjXWRwBW
pZVs8-evVrvWbnPoBA~TP3ATOtrSCGq1Ej_aLMEkFvgnlacq4S5Kx0an3_45jNE9ZrAg9
Dvm2hEtRQwYF_uEBIL17atsb2jo7y6tLthVQ
Figure 7: Issued JWP in Compact Serialization (es256)
To present this JPT, we first use the following presentation header
with a nonce (provided by the Verifier):
{
"alg": "SU-ES256",
"aud": "https://recipient.example.com",
"nonce": "mes_BFwj3Xc-T9r74gIlljf-9RWRvt2SV2NXI6HZpjI"
}
Figure 8: Presentation Header
This header is serialized without whitespace and UTF-8 encoded into
an octet string. This gives:
eyJhbGciOiJTVS1FUzI1NiIsImF1ZCI6Imh0dHBzOi8vcmVjaXBpZW50LmV4YW1wbGUuY
29tIiwibm9uY2UiOiJtZXNfQkZ3ajNYYy1UOXI3NGdJbGxqZi05UldSdnQyU1YyTlhJNk
hacGpJIn0
Figure 9: Presentation Header (base64url-encoded)
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When signed with the holder's presentation key, the resulting
signature are:
8CdaXdSvF4gt1wIO0P5iUKsNrE-KGEcE-myQsgNSmJ8mShMtbZdtnWvIGtLfImZcht_sC
LiRMFyrkG-DS3x-eA
| Figure: Holder Proof-of-Possession (base64url-encoded)
Then by applying selective disclosure of only the given name and age
claims (family name and email hidden), we get the following presented
JPT:
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{
"presentation": "eyJhbGciOiJTVS1FUzI1NiIsImF1ZCI6Imh0dHBzOi8vcmVjaX
BpZW50LmV4YW1wbGUuY29tIiwibm9uY2UiOiJtZXNfQkZ3ajNYYy1UOXI3NGdJ
bGxqZi05UldSdnQyU1YyTlhJNkhacGpJIn0",
"issuer": "eyJhbGciOiJTVS1FUzI1NiIsInR5cCI6IkpQVCIsImlzcyI6Imh0dHBz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",
"payloads": [
"MTcxNDUyMTYwMA",
"MTcxNzE5OTk5OQ",
"IkRvZSI",
"IkpheSI",
"ImpheWRvZUBleGFtcGxlLm9yZyI",
"eyJmb3JtYXR0ZWQiOiIxMjM0IE1haW4gU3QuXG5Bbnl0b3duLCBDQSAxMjM0NVxu
VVNBIiwic3RyZWV0X2FkZHJlc3MiOiIxMjM0IE1haW4gU3QuIiwibG9jYWxpdH
kiOiJBbnl0b3duIiwicmVnaW9uIjoiQ0EiLCJwb3N0YWxfY29kZSI6MTIzNDUs
ImNvdW50cnkiOiJVU0EifQ",
"dHJ1ZQ",
null,
null
],
"proof": [
"37RhnitI5rt3skZ9oRDpeGyxSynhvPxbhxe2_NDm4tQ8audwHH4nV7Qt7wN_vfNv
HZ_P3gkiNdrElSMBZcu1Xg",
"8CdaXdSvF4gt1wIO0P5iUKsNrE-KGEcE-myQsgNSmJ8mShMtbZdtnWvIGtLfImZc
ht_sCLiRMFyrkG-DS3x-eA",
"IIpR1uezrjhTgnVU4LY5KIdZOjayjRHFP6-ULHDv2ctMVSFTprkTpjvUwkgk1T2v
q6IHO5ptkISaglrWLur8vQ",
"sBFFXFVZKVuIoB2SiuyDCBSnC6Zkk10nWfsOn-I1CKAI0NC2QBxloc7gzxG4m4EN
SMKKpa9FKvyOtoBZi4YK2Q",
"svvidNTTnZU7D5Kze_SKBRhN3vJiUzs1bPQlK8_PIhqQrFhpKRiOI89Qqz6zqGdi
a1s8IfMYwNPoYJYIlYeNlw",
"yecfskC44VxcKWgZvUTWOXtp4EZ3kVYKAq1f_vCdPsxRkOrEsx7ADTXQtB0ksDhu
sEbwrqNP8ouNMSaHtKNucw",
"nMQ5lVAojfiJhzYYdKvL7kW35gXuquxrwAwntdjoNzfn7h6do63seUuSx8FUckdK
pDGODhWSCQtM6S38oc4Rcw"
]
}
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| Figure: Final Presentation in JSON Serialization
And also in compact serialization:
eyJhbGciOiJTVS1FUzI1NiIsImF1ZCI6Imh0dHBzOi8vcmVjaXBpZW50LmV4YW1wbGUuY
29tIiwibm9uY2UiOiJtZXNfQkZ3ajNYYy1UOXI3NGdJbGxqZi05UldSdnQyU1YyTlhJNk
hacGpJIn0.eyJhbGciOiJTVS1FUzI1NiIsInR5cCI6IkpQVCIsImlzcyI6Imh0dHBzOi8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.MTcxNDUyMTYwMA~MTcxNzE5OTk5OQ~IkRvZSI~IkpheS
I~ImpheWRvZUBleGFtcGxlLm9yZyI~eyJmb3JtYXR0ZWQiOiIxMjM0IE1haW4gU3QuXG5
Bbnl0b3duLCBDQSAxMjM0NVxuVVNBIiwic3RyZWV0X2FkZHJlc3MiOiIxMjM0IE1haW4g
U3QuIiwibG9jYWxpdHkiOiJBbnl0b3duIiwicmVnaW9uIjoiQ0EiLCJwb3N0YWxfY29kZ
SI6MTIzNDUsImNvdW50cnkiOiJVU0EifQ~dHJ1ZQ~~.37RhnitI5rt3skZ9oRDpeGyxSy
nhvPxbhxe2_NDm4tQ8audwHH4nV7Qt7wN_vfNvHZ_P3gkiNdrElSMBZcu1Xg~8CdaXdSv
F4gt1wIO0P5iUKsNrE-KGEcE-myQsgNSmJ8mShMtbZdtnWvIGtLfImZcht_sCLiRMFyrk
G-DS3x-eA~IIpR1uezrjhTgnVU4LY5KIdZOjayjRHFP6-ULHDv2ctMVSFTprkTpjvUwkg
k1T2vq6IHO5ptkISaglrWLur8vQ~sBFFXFVZKVuIoB2SiuyDCBSnC6Zkk10nWfsOn-I1C
KAI0NC2QBxloc7gzxG4m4ENSMKKpa9FKvyOtoBZi4YK2Q~svvidNTTnZU7D5Kze_SKBRh
N3vJiUzs1bPQlK8_PIhqQrFhpKRiOI89Qqz6zqGdia1s8IfMYwNPoYJYIlYeNlw~yecfs
kC44VxcKWgZvUTWOXtp4EZ3kVYKAq1f_vCdPsxRkOrEsx7ADTXQtB0ksDhusEbwrqNP8o
uNMSaHtKNucw~nMQ5lVAojfiJhzYYdKvL7kW35gXuquxrwAwntdjoNzfn7h6do63seUuS
x8FUckdKpDGODhWSCQtM6S38oc4Rcw
| Figure: Final Presentation in Compact Serialization
A.2. Example BBS JWP
The following example uses the BBS algorithm.
This is the Issuer's stable private key in the JWK format:
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{
"kty": "EC2",
"alg": "BBS",
"use": "proof",
"crv": "BLS12381G2",
"x": "CWEcZ-KBjqkcW9Kc1Hn3A7w5qKNpeenbz83LGWxZWOEIHzhdk7ZM1sBSlEcvQ
yS5EqSnJB6NHQQIsNPtBgehU9UlC3X-Bx-Y26YkIf4ZkTYrlE6TOUhsqxiIthn
149O8",
"y": "Ad9MtgXw9dUP26zjRrYZUiMGwP7RedzizTU16xQRF6mwHhduGVISfn5LvxfCJ
1JpAHbuN3_0bIhCaNTBLDsYBpDPT4YiV6ZfRyT76kMvkMPlIxxqmIG_jtaWzP8
sFR2p",
"d": "aeAX6WgqPjlQ_Jpp58jF-NNCCc7M9WGlQx20RUGWEJk"
}
Figure 10: BBS private key in JWK format
There is no additional holder key necessary for presentation proofs.
For the following protected header and array of payloads:
{
"kid": "HjfcpyjuZQ-O8Ye2hQnNbT9RbbnrobptdnExR0DUjU8",
"alg": "BBS"
}
Figure 11: Example issuer protected header
[
1714521600,
1717199999,
"Doe",
"Jay",
"[email protected]",
{
"formatted": "1234 Main St.\nAnytown, CA 12345\nUSA",
"street_address": "1234 Main St.",
"locality": "Anytown",
"region": "CA",
"postal_code": 12345,
"country": "USA"
},
true
]
Figure 12: Example issuer payloads (as members of a JSON array)
These components are signed using the private issuer key previously
given, which is then representable in the following serializations:
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{
"issuer": "eyJraWQiOiJIamZjcHlqdVpRLU84WWUyaFFuTmJUOVJiYm5yb2JwdGRu
RXhSMERValU4IiwiYWxnIjoiQkJTIn0",
"payloads": [
"MTcxNDUyMTYwMA",
"MTcxNzE5OTk5OQ",
"IkRvZSI",
"IkpheSI",
"ImpheWRvZUBleGFtcGxlLm9yZyI",
"eyJmb3JtYXR0ZWQiOiIxMjM0IE1haW4gU3QuXG5Bbnl0b3duLCBDQSAxMjM0NVxu
VVNBIiwic3RyZWV0X2FkZHJlc3MiOiIxMjM0IE1haW4gU3QuIiwibG9jYWxpdH
kiOiJBbnl0b3duIiwicmVnaW9uIjoiQ0EiLCJwb3N0YWxfY29kZSI6MTIzNDUs
ImNvdW50cnkiOiJVU0EifQ",
"dHJ1ZQ"
],
"proof": [
"gPypYJaCrnUwYPrPwRtD47Zk_KKaPc9FcUBs--XzmOF9xoUfQzANn1FdWZWd_1aT
Zt5l-jSaOtMARFhQrRkMIK-fz1bni7oBBquAEQcU3U8"
]
}
Figure 13: Issued JWP (JSON serialization)
eyJraWQiOiJIamZjcHlqdVpRLU84WWUyaFFuTmJUOVJiYm5yb2JwdGRuRXhSMERValU4I
iwiYWxnIjoiQkJTIn0.MTcxNDUyMTYwMA~MTcxNzE5OTk5OQ~IkRvZSI~IkpheSI~Imph
eWRvZUBleGFtcGxlLm9yZyI~eyJmb3JtYXR0ZWQiOiIxMjM0IE1haW4gU3QuXG5Bbnl0b
3duLCBDQSAxMjM0NVxuVVNBIiwic3RyZWV0X2FkZHJlc3MiOiIxMjM0IE1haW4gU3QuIi
wibG9jYWxpdHkiOiJBbnl0b3duIiwicmVnaW9uIjoiQ0EiLCJwb3N0YWxfY29kZSI6MTI
zNDUsImNvdW50cnkiOiJVU0EifQ~dHJ1ZQ.gPypYJaCrnUwYPrPwRtD47Zk_KKaPc9FcU
Bs--XzmOF9xoUfQzANn1FdWZWd_1aTZt5l-jSaOtMARFhQrRkMIK-fz1bni7oBBquAEQc
U3U8
Figure 14: Issued JWP (compact serialization)
For a presentation with the following presentation header:
{
"alg": "BBS",
"aud": "https://recipient.example.com",
"nonce": "wrmBRkKtXjQ"
}
Figure 15: Holder Presentation Header
The holder decides to share all information other than the email
address, and generates a proof. That proof is represented in the
following serializations:
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{
"presentation": "eyJhbGciOiJCQlMiLCJhdWQiOiJodHRwczovL3JlY2lwaWVudC
5leGFtcGxlLmNvbSIsIm5vbmNlIjoid3JtQlJrS3RYalEifQ",
"issuer": "eyJraWQiOiJIamZjcHlqdVpRLU84WWUyaFFuTmJUOVJiYm5yb2JwdGRu
RXhSMERValU4IiwiYWxnIjoiQkJTIn0",
"payloads": [
"MTcxNDUyMTYwMA",
"MTcxNzE5OTk5OQ",
"IkRvZSI",
"IkpheSI",
null,
null,
null
],
"proof": [
"iJG8Vt5P9LYtHStXxWF9lbxGi5x3lJ19MsGdrek-66i5ycvEFm1amYe5kjIaZHhg
iO0H2I1uQlhsyp88-lNLpGOM_XDzZwYqf4HTkLzorpGR5UVJrYLzP4HYAbdPCh
G8tfv9VxWarRRstGlNleoIf8qkUjvhbHWevX14Hjj102lif5aG4jEh71pYkifm
UxARJARKboAv2YWO8rCuzSy4NejsK81X6W93KJW8A_Om9z9myaqflqRP0Jp70z
4r2tYDBVDaOLCMd5DadMR6cfFkKDQMx-qCtb6rqxWRXwupEfie3PmRGHtOtJFN
7RZAv-TcQFREFqMnc80VYJFJhsbzaPjsSDcfyP-omMbr9bIg4F4wTFHrAtlFVY
Y_YdG_07DczJcTv35A6EdIaTpy9q_NCGlTj_wdRh0p3uNjZAKDG7as9dyQCzRA
LwiheQL03gtiTx4USV8yo2UXdsG-5hba4EYMs3YN2iwStQh91ZfzXRw"
]
}
Figure 16: Presentation JWP (JSON serialization)
eyJhbGciOiJCQlMiLCJhdWQiOiJodHRwczovL3JlY2lwaWVudC5leGFtcGxlLmNvbSIsI
m5vbmNlIjoid3JtQlJrS3RYalEifQ.eyJraWQiOiJIamZjcHlqdVpRLU84WWUyaFFuTmJ
UOVJiYm5yb2JwdGRuRXhSMERValU4IiwiYWxnIjoiQkJTIn0.MTcxNDUyMTYwMA~MTcxN
zE5OTk5OQ~IkRvZSI~IkpheSI~~~.iJG8Vt5P9LYtHStXxWF9lbxGi5x3lJ19MsGdrek-
66i5ycvEFm1amYe5kjIaZHhgiO0H2I1uQlhsyp88-lNLpGOM_XDzZwYqf4HTkLzorpGR5
UVJrYLzP4HYAbdPChG8tfv9VxWarRRstGlNleoIf8qkUjvhbHWevX14Hjj102lif5aG4j
Eh71pYkifmUxARJARKboAv2YWO8rCuzSy4NejsK81X6W93KJW8A_Om9z9myaqflqRP0Jp
70z4r2tYDBVDaOLCMd5DadMR6cfFkKDQMx-qCtb6rqxWRXwupEfie3PmRGHtOtJFN7RZA
v-TcQFREFqMnc80VYJFJhsbzaPjsSDcfyP-omMbr9bIg4F4wTFHrAtlFVYY_YdG_07Dcz
JcTv35A6EdIaTpy9q_NCGlTj_wdRh0p3uNjZAKDG7as9dyQCzRALwiheQL03gtiTx4USV
8yo2UXdsG-5hba4EYMs3YN2iwStQh91ZfzXRw
Figure 17: Presentation JWP (compact serialization)
A.3. Example MAC JWP
The following example uses the MAC-H256 algorithm.
This is the Issuer's stable private key in the JWK format:
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{
"kty": "EC",
"crv": "P-256",
"x": "rljcEFI0caNXx29jNkyLXtbPti5qHkokC6PWy9XYAeM",
"y": "I6OlSc34yeKQMvXvq4aV6M12ESAK9RkdArMIeAWi70M",
"d": "xa0e8RpopMldqZCT7g9-2gDlWM1PrHz1N-qoQOcXU6U"
}
Figure 18: Issuer private key
This is the Issuer's ephemerally generated shared secret:
"SFTuoixBgWpEjVC5SoNeklAanEpeRV5fHb2YmKBQ5yM"
Figure 19: Shared Secret
This is the Holder's presentation private key in the JWK format:
{
"kty": "EC",
"crv": "P-256",
"x": "y9wnI7zYYrkcXpd5j9O3qiRDMxmhPdNfbPzHtLIL_H0",
"y": "A2AJXiAYrlSGfwONgffXWaNnTXx-MXISPFRiwXMpEkg",
"d": "ZJco2u6h3y4g7M5otiVhTbfAEUSDMTkiSk76URi045c"
}
Figure 20: Holder private key
For the following protected header and array of payloads:
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{
"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": "y9wnI7zYYrkcXpd5j9O3qiRDMxmhPdNfbPzHtLIL_H0",
"y": "A2AJXiAYrlSGfwONgffXWaNnTXx-MXISPFRiwXMpEkg"
}
}
Figure 21: Example issuer protected header
[
1714521600,
1717199999,
"Doe",
"Jay",
"[email protected]",
{
"formatted": "1234 Main St.\nAnytown, CA 12345\nUSA",
"street_address": "1234 Main St.",
"locality": "Anytown",
"region": "CA",
"postal_code": 12345,
"country": "USA"
},
true
]
Figure 22: Example issuer payloads (as members of a JSON array)
The first MAC is generated using the key issuer_header and a value of
the issuer protected header as a UTF-8 encoded octet string. This
results in the following MAC:
GelNfHfj1MvbSqvtMLLrax2EWZa8Vk-kx3DvPU7yo6M
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Figure 23: Issuer MAC of protected header (base64url-encoded)
The issuer generates an array of derived keys with one for each
payload by using the shared secret as the key, and the index of the
payload (as payload_{n} in UTF-8 encoded octets) as the input in a
HMAC operation. This results in the following set of derived keys:
[
"YCXErQ0PO-_xVqoUJXU1GpBkLiKLUnRSPq9VNTGf3oo",
"fv76c2D2DkSVuV-wgzeNqt3mZTgJx_20K53LwRLbZPM",
"lloGHG190wV9wb3AC5rwbgR4qboSKHLG8dj63S4fYCA",
"UweEuEuHjhIL7Ot_S9R6qavLB3aUb7iwm3_Lr9aCpIg",
"DVGt1Km7Ff5KSHlgm-dK2ZVx9QwReBS5TyFa_QwYGdM",
"EBpCbeRdjPUqE3ikQJpEbwI3cd2SbL0Ygs61worKOzY",
"7qLtlKgAc6PZKZPKzhZStaMB-0HfEdcQdlofpf2gyy4"
]
Figure 24: Derived payload keys (base64url-encoded)
A MAC is generated for each payload using the corresponding derived
payload key. This results in the following set of MAC values:
[
"1YXUWZyWBUppXWc5ORe-4qHT-UHm4HGJtf_M3kAeWDo",
"Im8KqIkA1jLM05jWHCVgM_x2NBgiFl1UwV6e5VmEu6g",
"MVcytkCkQQCbtKorAAcFJ7ykGJhXwUo28WUjt5WPLjM",
"J4opViBopeg3w9lWjqU1VDe-aeEObjM9RgGdPa7Qido",
"T8TA_7VIvggxX6awElx5zsBIdnSMMHxJj3VnlEwOC3E",
"k1V5j6UGQRGIqHfzPdGSqCyPimLmUkVcizwRx7ZwArs",
"kNNUdBSfbsJI0fQENUejx7dfMDyvSr7HlhlzBnUD6oo"
]
Figure 25: Payload MAC values (base64url-encoded)
The issuer protected header MAC and the payload MAC octet strings are
concatenated into a single value known as the combined MAC
representation. This representation is signed with the issuer's
private key.
The proof consists of two octet string values: the signature over the
combined MAC representation, and the shared secret.
[
"4XWYLmnuc-J8PESgWfVMhcECJaLHuAohKymCfdc0pfMIqGYjDNqMQCJFU2nzltRk6K
E31ELCI8iUW2MV4eHPfA",
"oYLUf--sI9Ej2nDp-DiAMXe98MQEMMXSASw2zHUjETE"
]
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Figure 26: Issued Proof (base64url-encoded)
The final issued JWP in JSON serialization is:
{
"issuer": "eyJhbGciOiJNQUMtSDI1NiIsInR5cCI6IkpQVCIsImlzcyI6Imh0dHBz
Oi8vaXNzdWVyLmV4YW1wbGUiLCJjbGFpbXMiOlsiaWF0IiwiZXhwIiwiZmFtaWx5X25hb
WUiLCJnaXZlbl9uYW1lIiwiZW1haWwiLCJhZGRyZXNzIiwiYWdlX292ZXJfMjEiXSwicH
Jlc2VudGF0aW9uX2tleSI6eyJrdHkiOiJFQyIsImNydiI6IlAtMjU2IiwidXNlIjoic2l
nbiIsIngiOiJ5OXduSTd6WVlya2NYcGQ1ajlPM3FpUkRNeG1oUGROZmJQekh0TElMX0gw
IiwieSI6IkEyQUpYaUFZcmxTR2Z3T05nZmZYV2FOblRYeC1NWElTUEZSaXdYTXBFa2cif
X0",
"payloads": [
"MTcxNDUyMTYwMA",
"MTcxNzE5OTk5OQ",
"IkRvZSI",
"IkpheSI",
"ImpheWRvZUBleGFtcGxlLm9yZyI",
"eyJmb3JtYXR0ZWQiOiIxMjM0IE1haW4gU3QuXG5Bbnl0b3duLCBDQSAxMjM0NVxu
VVNBIiwic3RyZWV0X2FkZHJlc3MiOiIxMjM0IE1haW4gU3QuIiwibG9jYWxpdHkiOiJBb
nl0b3duIiwicmVnaW9uIjoiQ0EiLCJwb3N0YWxfY29kZSI6MTIzNDUsImNvdW50cnkiOi
JVU0EifQ",
"dHJ1ZQ"
],
"proof": [
"4XWYLmnuc-J8PESgWfVMhcECJaLHuAohKymCfdc0pfMIqGYjDNqMQCJFU2nzltRk
6KE31ELCI8iUW2MV4eHPfA",
"oYLUf--sI9Ej2nDp-DiAMXe98MQEMMXSASw2zHUjETE"
]
}
Figure 27: Issued JWP (in JSON serialization)
The same JWP in compact serialization:
eyJhbGciOiJNQUMtSDI1NiIsInR5cCI6IkpQVCIsImlzcyI6Imh0dHBzOi8vaXNzdWVyL
mV4YW1wbGUiLCJjbGFpbXMiOlsiaWF0IiwiZXhwIiwiZmFtaWx5X25hbWUiLCJnaXZlbl
9uYW1lIiwiZW1haWwiLCJhZGRyZXNzIiwiYWdlX292ZXJfMjEiXSwicHJlc2VudGF0aW9
uX2tleSI6eyJrdHkiOiJFQyIsImNydiI6IlAtMjU2IiwidXNlIjoic2lnbiIsIngiOiJ5
OXduSTd6WVlya2NYcGQ1ajlPM3FpUkRNeG1oUGROZmJQekh0TElMX0gwIiwieSI6IkEyQ
UpYaUFZcmxTR2Z3T05nZmZYV2FOblRYeC1NWElTUEZSaXdYTXBFa2cifX0.MTcxNDUyMT
YwMA~MTcxNzE5OTk5OQ~IkRvZSI~IkpheSI~ImpheWRvZUBleGFtcGxlLm9yZyI~eyJmb
3JtYXR0ZWQiOiIxMjM0IE1haW4gU3QuXG5Bbnl0b3duLCBDQSAxMjM0NVxuVVNBIiwic3
RyZWV0X2FkZHJlc3MiOiIxMjM0IE1haW4gU3QuIiwibG9jYWxpdHkiOiJBbnl0b3duIiw
icmVnaW9uIjoiQ0EiLCJwb3N0YWxfY29kZSI6MTIzNDUsImNvdW50cnkiOiJVU0EifQ~d
HJ1ZQ.4XWYLmnuc-J8PESgWfVMhcECJaLHuAohKymCfdc0pfMIqGYjDNqMQCJFU2nzltR
k6KE31ELCI8iUW2MV4eHPfA~oYLUf--sI9Ej2nDp-DiAMXe98MQEMMXSASw2zHUjETE
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Figure 28: Issued JWP (in compact serialization)
Next, we show the presentation of the JWP with selective disclosure.
For presentation with the following presentation protected header:
{
"alg": "MAC-H256",
"aud": "https://recipient.example.com",
"nonce": "mes_BFwj3Xc-T9r74gIlljf-9RWRvt2SV2NXI6HZpjI"
}
Figure 29: Presentation Protected Header
The holder will take the issuer proof (including shared secret) and
derive the same individual payload MAC values (above).
In this case, the holder has decided not to disclose the last three
claims provided by the issuer (corresponding to email, address, and
age_over_21)
For the disclosed payloads, the holder will provide the corresponding
derived key. For the non-disclosed payloads, the holder will provide
the corresponding MAC value.
The final presented proof value is an array of octet strings. The
contents are presentation header signature, followed by the issuer
signature, then the value disclosed by the holder for each payload.
This results in the following proof:
[
"bC1SXUSv9lVozHrbaYI2FtMgT1CjPySTee8LE261p_fRyxqFuF4b8eTMSkGsFxBS00
vtxeUK_vqySxUo2e6VeA",
"4XWYLmnuc-J8PESgWfVMhcECJaLHuAohKymCfdc0pfMIqGYjDNqMQCJFU2nzltRk6K
E31ELCI8iUW2MV4eHPfA",
"YCXErQ0PO-_xVqoUJXU1GpBkLiKLUnRSPq9VNTGf3oo",
"fv76c2D2DkSVuV-wgzeNqt3mZTgJx_20K53LwRLbZPM",
"lloGHG190wV9wb3AC5rwbgR4qboSKHLG8dj63S4fYCA",
"UweEuEuHjhIL7Ot_S9R6qavLB3aUb7iwm3_Lr9aCpIg",
"T8TA_7VIvggxX6awElx5zsBIdnSMMHxJj3VnlEwOC3E",
"k1V5j6UGQRGIqHfzPdGSqCyPimLmUkVcizwRx7ZwArs",
"kNNUdBSfbsJI0fQENUejx7dfMDyvSr7HlhlzBnUD6oo"
]
Figure 30: Presentation proof (base64url-encoded)
The final presented JWP in JSON serialization is:
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{
"presentation": "eyJhbGciOiJNQUMtSDI1NiIsImF1ZCI6Imh0dHBzOi8vcmVjaX
BpZW50LmV4YW1wbGUuY29tIiwibm9uY2UiOiJtZXNfQkZ3ajNYYy1UOXI3NGdJbGxqZi0
5UldSdnQyU1YyTlhJNkhacGpJIn0",
"issuer": "eyJhbGciOiJNQUMtSDI1NiIsInR5cCI6IkpQVCIsImlzcyI6Imh0dHBz
Oi8vaXNzdWVyLmV4YW1wbGUiLCJjbGFpbXMiOlsiaWF0IiwiZXhwIiwiZmFtaWx5X25hb
WUiLCJnaXZlbl9uYW1lIiwiZW1haWwiLCJhZGRyZXNzIiwiYWdlX292ZXJfMjEiXSwicH
Jlc2VudGF0aW9uX2tleSI6eyJrdHkiOiJFQyIsImNydiI6IlAtMjU2IiwidXNlIjoic2l
nbiIsIngiOiJ5OXduSTd6WVlya2NYcGQ1ajlPM3FpUkRNeG1oUGROZmJQekh0TElMX0gw
IiwieSI6IkEyQUpYaUFZcmxTR2Z3T05nZmZYV2FOblRYeC1NWElTUEZSaXdYTXBFa2cif
X0",
"payloads": [
"MTcxNDUyMTYwMA",
"MTcxNzE5OTk5OQ",
"IkRvZSI",
"IkpheSI",
null,
null,
null
],
"proof": [
"bC1SXUSv9lVozHrbaYI2FtMgT1CjPySTee8LE261p_fRyxqFuF4b8eTMSkGsFxBS
00vtxeUK_vqySxUo2e6VeA",
"4XWYLmnuc-J8PESgWfVMhcECJaLHuAohKymCfdc0pfMIqGYjDNqMQCJFU2nzltRk
6KE31ELCI8iUW2MV4eHPfA",
"YCXErQ0PO-_xVqoUJXU1GpBkLiKLUnRSPq9VNTGf3oo",
"fv76c2D2DkSVuV-wgzeNqt3mZTgJx_20K53LwRLbZPM",
"lloGHG190wV9wb3AC5rwbgR4qboSKHLG8dj63S4fYCA",
"UweEuEuHjhIL7Ot_S9R6qavLB3aUb7iwm3_Lr9aCpIg",
"T8TA_7VIvggxX6awElx5zsBIdnSMMHxJj3VnlEwOC3E",
"k1V5j6UGQRGIqHfzPdGSqCyPimLmUkVcizwRx7ZwArs",
"kNNUdBSfbsJI0fQENUejx7dfMDyvSr7HlhlzBnUD6oo"
]
}
Figure 31: Presented JWP (in JSON serialization)
The same JWP in compact serialization:
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eyJhbGciOiJNQUMtSDI1NiIsImF1ZCI6Imh0dHBzOi8vcmVjaXBpZW50LmV4YW1wbGUuY
29tIiwibm9uY2UiOiJtZXNfQkZ3ajNYYy1UOXI3NGdJbGxqZi05UldSdnQyU1YyTlhJNk
hacGpJIn0.eyJhbGciOiJNQUMtSDI1NiIsInR5cCI6IkpQVCIsImlzcyI6Imh0dHBzOi8
vaXNzdWVyLmV4YW1wbGUiLCJjbGFpbXMiOlsiaWF0IiwiZXhwIiwiZmFtaWx5X25hbWUi
LCJnaXZlbl9uYW1lIiwiZW1haWwiLCJhZGRyZXNzIiwiYWdlX292ZXJfMjEiXSwicHJlc
2VudGF0aW9uX2tleSI6eyJrdHkiOiJFQyIsImNydiI6IlAtMjU2IiwidXNlIjoic2lnbi
IsIngiOiJ5OXduSTd6WVlya2NYcGQ1ajlPM3FpUkRNeG1oUGROZmJQekh0TElMX0gwIiw
ieSI6IkEyQUpYaUFZcmxTR2Z3T05nZmZYV2FOblRYeC1NWElTUEZSaXdYTXBFa2cifX0.
MTcxNDUyMTYwMA~MTcxNzE5OTk5OQ~IkRvZSI~IkpheSI~~~.bC1SXUSv9lVozHrbaYI2
FtMgT1CjPySTee8LE261p_fRyxqFuF4b8eTMSkGsFxBS00vtxeUK_vqySxUo2e6VeA~4X
WYLmnuc-J8PESgWfVMhcECJaLHuAohKymCfdc0pfMIqGYjDNqMQCJFU2nzltRk6KE31EL
CI8iUW2MV4eHPfA~YCXErQ0PO-_xVqoUJXU1GpBkLiKLUnRSPq9VNTGf3oo~fv76c2D2D
kSVuV-wgzeNqt3mZTgJx_20K53LwRLbZPM~lloGHG190wV9wb3AC5rwbgR4qboSKHLG8d
j63S4fYCA~UweEuEuHjhIL7Ot_S9R6qavLB3aUb7iwm3_Lr9aCpIg~T8TA_7VIvggxX6a
wElx5zsBIdnSMMHxJj3VnlEwOC3E~k1V5j6UGQRGIqHfzPdGSqCyPimLmUkVcizwRx7Zw
Ars~kNNUdBSfbsJI0fQENUejx7dfMDyvSr7HlhlzBnUD6oo
Figure 32: Presented JWP (in compact serialization)
Appendix B. Acknowledgements
This work was incubated in the DIF Applied Cryptography Working Group
(https://identity.foundation/working-groups/crypto.html).
We would like to thank Alberto Solavagione for his valuable
contributions to this specification.
The BBS examples were generated using the library at
https://github.com/mattrglobal/pairing_crypto
(https://github.com/mattrglobal/pairing_crypto) .
Appendix C. Document History
[[ To be removed from the final specification ]]
-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.
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* 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.
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-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: [email protected]
URI: https://self-issued.info/
David Waite
Ping Identity
Email: [email protected]
Jeremie Miller
Ping Identity
Email: [email protected]
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