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<!DOCTYPE html>
<html>
<head>
<title>Verifiable Credentials Data Model 1.0</title>
<meta http-equiv='Content-Type' content='text/html;charset=utf-8'/>
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// subtitle for the spec
subtitle: "Expressing verifiable information on the Web",
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<body>
<section id='abstract'>
<p>
Credentials are a part of our daily lives;
driver's licenses are used to assert that we are capable of operating a motor
vehicle, university degrees can be used to assert our level of education, and
government-issued passports enable holders to travel between countries.
This specification provides a mechanism to express these sorts of
credentials on the Web in a way that is cryptographically secure,
privacy respecting, and machine-verifiable.
</p>
</section>
<section id='sotd'>
<p>
Comments regarding this document are welcome. Please file issues
directly on <a href="https://github.com/w3c/vc-data-model/issues/">GitHub</a>,
or send them to
<a href="mailto:[email protected]">[email protected]</a>
(<a href="mailto:[email protected]?subject=subscribe">subscribe</a>,
<a href="https://lists.w3.org/Archives/Public/public-vc-comments/">archives</a>).
</p>
</section>
<section>
<h2>Introduction</h2>
<em>This section is non-normative.</em>
<p>
Credentials are a part of our daily lives; driver's licenses are used to
assert that we are capable of operating a motor vehicle, university degrees
can be used to assert our level of education, and government-issued passports
enable us to travel between countries. These credentials provide benefits
to us when used in the physical world, but their use on the Web continues to
be elusive.
</p>
<p>
It is currently difficult to express banking account information,
education qualifications, healthcare data, and other sorts of machine-readable
personal information that has been verified by a 3rd party on the Web and this
makes it difficult to receive the same benefits from the Web that physical
credentials provide us in the physical world.
</p>
<p>
This specification provides a
standard way to express credentials on the Web in a way that is
cryptographically secure, privacy respecting, and machine-verifiable.
</p>
<p>
For those that are unfamiliar with the concepts related to verifiable credentials,
the following sections provide an overview of:
</p>
<ol>
<li>
what a verifiable credential contains,
</li>
<li>
what a presentation (derived from verifiable credential) contains,
</li>
<li>
an ecosystem where verifiable credentials and presentations are expected to be useful, and
</li>
<li>
the use cases and requirements that informed this specification
</li>
</ol>
</p>
<section>
<h3> Overview</h3>
<section>
<h3>What is a Verifiable Credential?</h3>
<p>
In the physical world, a credential may consist of:
</p>
<ul>
<li>
information related to the subject of the credential (e.g. photo, name, and
identification number),
</li>
<li>
information related to the issuing authority (e.g. city government,
national agency, or certification body),
</li>
<li>
evidence related to how the credential was derived, and
</li>
<li>
information related to expiration dates.
</li>
</ul>
<p>
A verifiable credential is capable of representing all of the same information
that a physical credential is intended to represent. The addition of
digital technologies, such as digital signatures, also make verifiable
credentials more tamperproof and therefore more trustworthy
than their physical counterparts. Verifiable credentials and presentations can also be
rapidly exchanged through the Internet, making them more convenient than
their physical counterparts when needing to establish trust at a distance.
</p>
</section>
<section>
<h3>What is a Presentation?</h3>
<p>
Holders can generate presentations and share them with a verifier to prove
they possess verifiable credentials with certain characteristics.
</p>
</section>
</section>
<section>
<h3>Ecosystem Overview</h3>
<em>This section is non-normative.</em>
<p>
This section outlines a basic set of roles and an ecosystem where verifiable
credentials are expected to be useful. In this section, we distinguish the essential
roles of core actors and the relationships between them; how do they interact?
A role is an abstraction that might be implemented in many different ways. The
separation of roles suggests likely interfaces and/or protocols for
standardization. The following roles are introduced in this specification:
</p>
<dl>
<dt><a>holder</a></dt>
<dd>
A role an <a>entity</a> may perform by possessing one or more
<a>verifiable credentials</a> and generating <a>presentations</a> from them. Examples of holders include students,
employees, and customers.
</dd>
<dt><a>issuer</a></dt>
<dd>
A role an <a>entity</a> may perform by creating a <a>verifiable credential</a>,
associating it with a particular <a>subject</a>, and transmitting it to
a <a>holder</a>. Examples of issuers include corporations, non-profits,
trade associations, governments, and individuals.
</dd>
<dt><a>verifier</a></dt>
<dd>
A role an <a>entity</a> may perform by requesting and receiving a
<a>presentation</a> that proves the holder possesses verifiable credentials with certain characteristics.
Examples of verifiers include employers, security personnel, and websites.
</dd>
<dt><a>Verifiable data repository</a></dt>
<dd>
A role a system may perform by mediating the creation and verification of
<a>issuer</a> identifiers, keys and other relevant data required to verify presentations. Examples of such data repositories include
corporate employee databases, government ID databases, and distributed ledgers.
</dd>
</dl>
<figure>
<img style="margin: auto; display: block;" width="75%" src="diagrams/ecosystem.svg">
<figcaption style="text-align: center;">
The roles and information flows that form the basis for this specification.
</figcaption>
</figure>
<p class="note">
The ecosystem above is provided as an example to the reader in order to ground
the rest of the concepts in this specification. Other ecosystems exist, such as
protected environments or proprietary systems, where verifiable credentials also
provide benefit.
</p>
<p class="issue" data-number=57>
The VCWG is actively discussing the number of roles and terminology used
in this specification.
The group expects terminology and role identification to be an ongoing
discussion and will be influenced by
public feedback on the specification. At present, the following incomplete
list of roles and terminology have been considered: Subject, Issuer, Authority,
Author, Signatory, Holder, Presenter, Asserter, Claimant, Sharer,
Subject's Agent, Prover, Mediator, Inspector, Evaluator, Verifier, Consumer, and
Relying Party. Some of these are aliases for the same concept, others are
possibly new roles in the ecosystem. Reviewers should be aware that the
terminology used in this document is not necessarily final and the group is
actively soliciting feedback on the roles and terminology used in this
specification.
</p>
<p class="issue" data-number=80>
The group is currently discussing how the ecosystem overview could be improved
with the intent to defer future improvements as the current section seems to
be working well so far.
</p>
<p class="issue" data-number=32>
The group is currently discussing how to bootstrap simple Web of Trust
credentials in this ecosystem.
</p>
</section>
<section>
<h3>Use Cases and Requirements</h3>
<em>This section is non-normative.</em>
<p>
The Verifiable Credentials Use Cases[[VC-USECASES]] document outlines a number of
key topics that readers may find useful, including:
</p>
<ul>
<li>
a more thorough explanation of the
<a href="https://www.w3.org/TR/verifiable-claims-use-cases/#user-roles">roles</a>
introduced above,
</li>
<li>
the
<a href="https://www.w3.org/TR/verifiable-claims-use-cases/#user-needs">needs</a>
identified in market verticals like education, finance, healthcare, retail,
professional licensing, and government,
</li>
<li>
common
<a href="https://www.w3.org/TR/verifiable-claims-use-cases/#user-tasks">tasks</a>
performed by the roles in the ecosystem, as well as their associated
requirements, and
</li>
<li>
common
<a href="https://www.w3.org/TR/verifiable-claims-use-cases/#user-sequences">sequences and flows</a>
identified by the Working Group.
</li>
</ul>
<p>
As a result of documenting and analyzing the use cases document, a number of
desirable ecosystem characteristics have been identified for this
specification, namely:
</p>
<ul>
<li>
<a>Holders</a> receive and store <a>verifiable credentials</a> from
<a>issuers</a>.
</li>
<li>
<a>Holders</a> may use an agent that the issuer does not need to trust.
</li>
<li>
<a>Holders</a> are positioned between <a>issuers</a> and <a>verifiers</a>.
</li>
<li>
<a>Holders</a> generate <a>proofs</a> of their <a>verifiable credentials</a> as needed and provide these <a>proofs</a> to <a>verifiers</a>.
</li>
<li>
<a>Holders</a> may use an agent that verifiers needn't trust; they only need to trust
<a>issuers</a>.
</li>
<li>
<a>Verifiable credentials</a> are associated with <a>subjects</a>, not
particular services; <a>holders</a> decide how to aggregate and manage
<a>verifiable credentials</a>.
</li>
<li>
<a>Holders</a> are able to easily control and own their own identifiers.
</li>
<li>
<a>Holders</a> control which <a>verifiable credentials</a> to use and when.
</li>
<li>
<a>Holders</a> are be able to freely choose and change the agents they employ
to help them manage their <a>verifiable credentials</a> and generate and share <a>proofs</a>.
</li>
<li>
<a>Holders</a> that share <a>proofs</a> are not required to
reveal the identity of the <a>verifier</a> to <a>issuers</a>.
</li>
<li>
<a>Verifiable credentials</a> and <a>proofs</a> are expressed in one or more standard,
machine-readable data formats which can also be extended with minimal
coordination.
</li>
<li>
<a>Verifiable credentials</a> are independently issued and stored. <a>Proofs</a> are independently verified.
</li>
<li>
<a>Verifiable Credentials</a> can be revoked by the <a>issuer</a>.
</li>
</ul>
<p class="issue">
There are
<a href="https://www.w3.org/TR/verifiable-claims-use-cases/#user-tasks">other requirements</a>
listed in the Verifiable Credentials Use Cases
document that may or may not be aligned with the requirements listed above.
The VCWG will be ensuring alignment of the list of requirements from both
documents over time and will most likely move the list of requirements to a
single document.
</p>
</section>
</section>
<section>
<h2>Terminology</h2>
<em>This section is non-normative.</em>
<div data-include="./terms.html"
data-oninclude="restrictReferences">
</div>
</section>
<section>
<h2>Core Data Model</h2>
<em>This section is non-normative.</em>
<p>
The following sections outline core data model concepts, such as
<a>claims</a>, <a>credentials</a>, and <a>presentations</a>, that form the
foundation of this specification.
</p>
<section>
<h3>Claims</h3>
<em>This section is non-normative.</em>
<p>
A <a>claim</a> is statement about a <a>subject</a>.
A <a>subject</a> is an <a>entity</a> about which <a>claims</a> may be made.
<a>Claims</a> are expressed using
<strong><em>subject</em></strong>-<dfn data-lt="property|properties">property</dfn>-<dfn>value</dfn>
relationships.
</p>
<figure>
<img style="margin: auto; display: block;"
width="50%" src="diagrams/claim.svg">
<figcaption style="text-align: center;">
The basic structure of a claim.
</figcaption>
</figure>
<p>
The data model for <a>claims</a> described above is powerful and can be used to
express a large variety of statements. For example, a claim specifying the data of birth of a subject
can be used to prove that its age lies in an interval or is greater or less than a some value which is
needed in use cases like proving drinking age or teenager discount or elderly discount;
the holder has the flexibility to use the claim in any way that is applicable to that claim:
</p>
<!-- TODO: Update the next picture -->
<figure>
<img style="margin: auto; display: block;"
width="50%" src="diagrams/claim-example.svg">
<figcaption style="text-align: center;">
An example of a basic claim that expresses that Pat is over the age of 21.
</figcaption>
</figure>
<p>
These claims may be merged together to express a graph of
information about a particular subject. The example below extends the
data model above by adding claims that state that Pat knows Sam and that
Sam is employed as a professor.
</p>
<!-- TODO: Update the next picture -->
<figure>
<img style="margin: auto; display: block;"
width="75%" src="diagrams/claim-extended.svg">
<figcaption style="text-align: center;">
Multiple claims may be combined to express a more complex graph.
</figcaption>
</figure>
<p>
At this point, the concept of a <a>claim</a> has been introduced. To enable
one to trust the claims, more information must be added to the graph
of information.
</p>
</section>
<section>
<h2>Credentials</h2>
<em>This section is non-normative.</em>
<p>
A <a>credential</a> is set of one or more <a>claims</a> made by the
same <a>entity</a>. It may include an identifier to uniquely identify the
credential which helps in revoking the credential, as well as metadata that
describes properties of the credential itself such as: the <a>issuer</a>,
the public key to use, the revocation mechanism to use etc. This metadata can
either be signed by the issuer or not, more on that later. The credential identifier
is never revealed to the verifier to prevent the issuer and verifier from
colluding to correlate the verifier.
A <a>verifiable credential</a> is a set of claims and meta data that are
tamper-resistant and that cryptographically prove who issued it.
</p>
<!-- TODO: Update the next picture to show the keys, schema, etc-->
<figure>
<img style="margin: auto; display: block;" width="50%" src="diagrams/credential.svg">
<figcaption style="text-align: center;">
The basic components of a verifiable credential.
</figcaption>
</figure>
<p>
Examples of verifiable credentials include digital employee identification
cards, digital birth certificates, digital educational certificates, etc.
</p>
<p class="note">
It is possible to have a <a>credential</a>, such as a marriage certificate,
that contains multiple <a>claims</a> about different <a>subjects</a> that are
not required to be related.
</p>
<p class="issue" data-number=47>
The group is currently discussing whether or not they support all the types
of claims that can be made.
</p>
</section>
<section>
<h2>Presentations</h2>
<em>This section is non-normative.</em>
<p>
As this specification takes a privacy-first approach, it is important that
the entities that use this technology are able to express only the portions of
their persona that are appropriate for the situation. The expression of a
subset of one's persona is called a <a>verifiable presentation</a>.
</p>
<p>
A <a>verifiable presentation</a> is generated from one or more
<a>verifiable credentials</a> that are often about the same <a>subject</a> that
have been issued by multiple <a>issuers</a>. The aggregation of this
information typically expresses an aspect of a person, organization, or entity.
</p>
<!-- TODO: Update the next picture-->
<figure>
<img style="margin: auto; display: block;"
width="50%" src="diagrams/presentation.svg">
<figcaption style="text-align: center;">
The basic components of a verifiable presentation.
</figcaption>
</figure>
<p>
Examples of different presentations include a person's professional persona, online
gaming persona, or home life persona.
</p>
<p class="note">
It is possible to generate a <a>presentation</a>, such as in the context of a business persona,
that is derived from multiple <a>credentials</a> about different <a>subjects</a>
that are often, but not required to be, related.
</p>
</section>
</section>
<section>
<h1>Trust Model</h1>
<em>This section is non-normative.</em>
<p>
The Verifiable Credentials trust model is as follows:
</p>
<ol>
<li>
The <a>verifier</a> trusts the <a>issuer</a> to issue the <a>credential</a>
that it receives. In order to establish this trust, a credential MUST
either 1) include a <a href="#proofs-aka-signatures">proof</a> that establishes
that the issuer generated the credential (it is a <a>verifiable credential</a>),
or 2) have been transmitted in a way that clearly establishes that the
issuer generated the credential and that the credential has not been tampered
with in transit or storage. This trust could be weakened depending upon the
risk assessment of the verifier.
</li>
<li>
All entities trust the <a>identifier registry</a> to be un-corruptible and
to be a correct record of which data is owned (and can be updated) by which
<a>entities</a>.
</li>
<li>
The <a>subject</a> trusts (since only the holder can verify) the <a>issuer</a> to issue true (i.e. not false)
<a>credentials</a> about the subject, and to revoke them quickly when
appropriate.
</li>
</ol>
<p>
This trust model differentiates itself from other trust models by ensuring that
the <a>issuer</a> does not need to trust (or even know) the <a>verifier</a>.
</p>
<p>
By decoupling the trust between the <a>identity provider</a> and the
<a>relying party</a>, a more flexible and dynamic trust model is created
such that market competition and customer choice is increased.
</p>
</section>
<section>
<h1>Basic Concepts</h1>
<p>
This section outlines some of the basic concepts introduced in this
specification and lays the groundwork for the more advanced concepts
toward the end of the document.
</p>
<section>
<h2>Types</h2>
<p>
Software systems that process the objects specified in this document
use type information to make determinations about whether or not the provided
<a>credential</a> or <a>presentation</a> is appropriate.
Type information MUST be expressed via the <a>type</a> property:
</p>
<p class="issue" data-number=183>
The group is currently debating the contents of the type property.
</p>
<dl>
<dt><dfn>type</dfn></dt>
<dd>
The value of this property MUST be or map to one or more URIs.
If more than one URI is provided, the URIs MUST be interpreted as an
unordered set. Note that syntactic conveniences, such as JSON-LD terms,
SHOULD be used to ease developer usage. It is RECOMMENDED that dereferencing
the URI results in a document containing machine-readable information about
the type.
</dd>
</dl>
<pre class="example nohighlight" title="Usage of the type property">
{
"id": "http://dmv.example.gov/credentials/3732",
<span class="highlight">"type": ["VerifiableCredential", "ProofOfAgeCredential"]</span>,
"claim": {
"id": "did:example:ebfeb1f712ebc6f1c276e12ec21",
"ageOver": 21
},
"proof": { ... }
}
</pre>
<p>
With respect to this specification, the following <a>type</a>s MUST be
specified on the following objects:
</p>
<table class="simple">
<thead>
<tr>
<th>Concept</th>
<th>Type</th>
</tr>
</thead>
<tbody>
<tr>
<td>
A <a href="#credentials">credential</a> object
</td>
<td>
<tt>"type": ["<code>VerifiableCredential</code>"]</tt> and
a more specific credential type (e.g. <code>ProofOfAgeCredential</code>)
</td>
</tr>
<tr>
<td>
A <a href="#presentations">presentation</a> object
</td>
<td>
<tt>"type": ["<code>VerifiablePresentation</code>"]</tt> and optionally a
more specific presentation type
(e.g. <code>CredentialManagerPresentation</code>).
</td>
</tr>
<tr>
<td>
A <a href="#status">credentialStatus</a> object
</td>
<td>
A valid credential status type (e.g. <code>CredentialStatusList2017</code>)
</td>
</tr>
<tr>
<td>
A <a href="#terms-of-use">termsOfUse</a> object
</td>
<td>
A valid terms of use type (e.g. <code>OdrlPolicy2017</code>)
</td>
</tr>
<tr>
<td>
An <a href="#terms-of-use">evidence</a> object
</td>
<td>
A valid evidence type (e.g. <code>DocumentVerification2018</code>)
</td>
</tr>
</tbody>
</table>
<p>
All <a>credentials</a>, <a>presentations</a>, and encapsulated objects MUST
specify or be associated with additional, more narrow <a>type</a>s
(e.g. <code>ProofOfAgeCredential</code>) such that software systems can use
the additional information to more easily process the data.
</p>
<p>
When processing encapsulated objects in this specification, (e.g. objects
associated with the <code>claim</code> property or deeply nested therein),
a software system SHOULD use type information specified in encapsulating
objects higher in the hierarchy. For the avoidance of doubt, an
encapsulating object such as <a>credential</a>, SHOULD convey the types of
associated objects so that the <a>verifier</a> can quickly determine the
contents of the associated object based on the type of the encapsulating object.
To provide a concrete example, a <a>credential</a> with the additional
<code>type</code> of <code>ProofOfAgeCredential</code> would signal to the
<a>verifier</a> that the object associated with the <a>claim</a> property will
contain the identifier for the <a>subject</a> in the <code>id</code> property
and the age assertion in the <code>ageOver</code> property. This enables
implementers to rely on values associated with the <code>type</code> property
for verification purposes. The expectation of types and their associated
properties SHOULD be documented in at least a human-readable specification,
and preferably in an additional machine-readable representation.
</p>
<p class="note">
The type system for the Verifiable Credentials Data Model is the same as the
one for [[JSON-LD]] and is detailed in
<a href="https://www.w3.org/TR/json-ld/#specifying-the-type">Section 5.4: Specifying the Type</a>
and
<a href="https://www.w3.org/TR/json-ld/#json-ld-grammar">Section 8: JSON-LD Grammar</a>.
When using a JSON-LD Context (see Section <a href="#extensibility"></a>),
this specification aliases the <code>@type</code>
keyword to <code>type</code> in order to make the JSON-LD documents more
idiomatic. While application developers and document authors do not need to
understand the specifics of JSON-LD's type system, implementers of this
specification that want to support extensibility in an interoperable fashion do.
</p>
<p class="issue" data-number=123>
The group is currently discussing whether or not JSON Object Types should be
explicitly stated.
</p>
</section>
<section>
<h2>Issuer</h2>
<p>
Issuer information may be expressed via the following <a>properties</a>:
</p>
<dl>
<dt><var>issuer</var></dt>
<dd>
The value of this property MUST be a URI. It is RECOMMENDED that dereferencing
the URI results in a document containing machine-readable information about
the issuer that may be used to verify the information expressed in the
<a>credential</a>.
</dd>
<dt><var>issuanceDate</var></dt>
<dd>
The value of this property MUST be a string value of an [[!ISO8601]] combined
date and time string and represents the date and time the <a>credential</a>
was issued. Note that this date represents the earliest date when the
information associated with the <var>claim</var> property became valid.
</dd>
</dl>
<pre class="example nohighlight" title="Usage of issuer properties">
{
"id": "http://dmv.example.gov/credentials/3732",
"type": ["VerifiableCredential", "ProofOfAgeCredential"],
<span class="highlight">"issuer": "https://dmv.example.gov/issuers/14"</span>,
<span class="highlight">"issuanceDate": "2010-01-01T19:73:24Z"</span>,
"claim": {
"id": "did:example:ebfeb1f712ebc6f1c276e12ec21",
"ageOver": 21
},
"proof": { ... }
}
</pre>
</section>
<section>
<h2>Proofs (aka Signatures)</h2>
<p>
In order for a <a>credential</a> or <a>presentation</a> to be made
verifiable, the following property MUST be present:
</p>
<dl>
<dt><var>proof</var></dt>
<dd>
The method used for a mathematical proof will vary by representation language
and the technology used. For example, if digital signatures are used for
the proof mechanism, this property is expected to have a value that is a
set of name-value pairs including at least a signature, a reference to the
signing entity, and a representation of the signing date.</dd>
</dl>
<pre class="example nohighlight"
title="Usage of proof property on a verifiable credential">
{
"id": "http://example.gov/credentials/3732",
"type": ["VerifiableCredential", "ProofOfAgeCredential"],
"issuer": "https://dmv.example.gov",
"issuanceDate": "2010-01-01",
"claim": {
"id": "did:example:ebfeb1f712ebc6f1c276e12ec21",
"ageOver": 21
},
<span class="highlight">"proof": {
"type": "RsaSignature2018",
"created": "2017-06-18T21:19:10Z",
"creator": "https://example.com/jdoe/keys/1",
"nonce": "c0ae1c8e-c7e7-469f-b252-86e6a0e7387e",
"signatureValue": "BavEll0/I1zpYw8XNi1bgVg/sCneO4Jugez8RwDg/+
MCRVpjOboDoe4SxxKjkCOvKiCHGDvc4krqi6Z1n0UfqzxGfmatCuFibcC1wps
PRdW+gGsutPTLzvueMWmFhwYmfIFpbBu95t501+rSLHIEuujM/+PXr9Cky6Ed
+W3JT24="
}</span>
}
</pre>
<p class="issue" data-number=93>
The group is currently discussing various alignments with the JOSE stack,
specifically JWS and JWK.
</p>
</section>
<section>
<h2>Expiration</h2>
<p>
Expiration information for the <a>credential</a> MAY be provided by adding
the following <a>property</a>:
</p>
<dl>
<dt><var>expirationDate</var></dt>
<dd>
The value of this property MUST be a string value of an [[!ISO8601]] combined
date and time string and represents the date and time the <a>credential</a>
will cease to be valid.
</dd>
</dl>
<pre class="example nohighlight" title="Usage of expirationDate property">
{
"id": "http://dmv.example.gov/credentials/3732",
"type": ["VerifiableCredential", "ProofOfAgeCredential"],
"issuer": "https://dmv.example.gov/issuers/14",
"issuanceDate": "2010-01-01T19:73:24Z",
<span class="highlight">"expirationDate": "2020-01-01T19:73:24Z"</span>,
"claim": {
"id": "did:example:ebfeb1f712ebc6f1c276e12ec21",
"ageOver": 21
},
"proof": { ... }
}
</pre>
<p class="issue" data-number=164>
The group is currently discussing expiration and caching.
</p>
<p class="issue" data-number=19>
The group is currently discussing how to automatically renew credentials.
</p>
<p class="issue" data-number=139>
The group is currently discussing how verifiable credentials may be
automatically updated.
</p>
</section>
<section>
<h2>Status</h2>
<p>Information about the current status of a <a>verifiable credential</a>,
such as suspension or revocation,
may be provided by adding the <code>credentialStatus</code> <a>property</a>.
This property
comprises the type of credential status information that is being provided
(sometimes referred to as the credential status scheme), plus the id of the status
type instance. The precise contents of the credential status information is
determined by the specific <code>credentialStatus</code> type definition,
and will vary
depending upon a variety of factors, such as whether it is
simple to implement or privacy-enhancing.
</p>
<dl>
<dt><var>credentialStatus</var></dt>
<dd>The value of this property MUST be a credential status scheme that
provides enough information to determine the current status of the
credential (e.g. suspended, revoked, etc.).
</dd>
</dl>
<pre class="example nohighlight" title="Usage of status property">
{
"id": "http://dmv.example.gov/credentials/3732",
"type": ["VerifiableCredential", "ProofOfAgeCredential"],
"issuer": "https://dmv.example.gov/issuers/14",
"issuanceDate": "2010-01-01T19:73:24Z",
"claim": {
"id": "did:example:ebfeb1f712ebc6f1c276e12ec21",
"ageOver": 21
},
<span class="highlight">"credentialStatus": {
"id": "https://dmv.example.gov/status/24,
"type": "CredentialStatusList2017"
}</span>,
"proof": { ... }
}
</pre>
<p>
Defining the data model, formats, and protocols for status schemes are out
of scope for this specification. A status scheme registry [[VC-STATUS-REGISTRY]]
exists for implementers that would like to implement credential status checking.
</p>
</section>
<section>
<h2>Presentations</h2>
<p>
Credentials MAY be composed by placing them into a data structure called a
<a>presentation</a>. A <a>verifiable presentation</a> is a presentation that contains
<a>verifiable credentials</a> and one or more proofs that are appropriate
for the presentation. The basic structure of a <a>verifiable presentation</a>
is provided below:
</p>
<pre class="example nohighlight" title="Basic structure of a presentation">
{
"id": "urn:uuid:3978344f-8596-4c3a-a978-8fcaba3903c5",
"type": ["VerifiablePresentation"],
<span class="highlight">"verifiableCredential": [{ ... }],
"proof": [{ ... }]</span>
}
</pre>
<p class="issue" data-number=133>
The group is currently discussing whether the "id" field is appropriately
defined for Presentations.
</p>
<p class="issue" data-number=120>
The group is currently discussing whether the "id" field is appropriately
defined across all objects.
</p>
<p class="issue" data-number=106>
The group is currently discussing how the data model expresses when the
subject is not the holder of the credential/presentation.
</p>
<p class="issue" data-number=105>
The group is currently discussing holders, subjects, and identifier
control.
</p>
<p>
The contents of the <code>verifiableCredential</code> property are
<a>verifiable credentials</a> as described by this specification. The contents
of the <code>proof</code> property are proofs as described by the