terms.html

<p>
The following terms are used to describe concepts in this specification.
</p>

<dl class="termlist">
  <dt><dfn data-lt="claims">claim</dfn></dt>
  <dd>
An assertion made about a <a>subject</a>.
  </dd>
  <dt><dfn data-lt="credential|credentials|credential's">credential</dfn></dt>
  <dd>
A set of one or more <a>claims</a> made by an <a>issuer</a>. A
<dfn data-lt="verifiable credentials">verifiable credential</dfn> is a
tamper-evident credential that has authorship that can be cryptographically
verified. Verifiable credentials can be used to build
<a>verifiable presentations</a>, which can also be cryptographically verified.
The <a>claims</a> in a credential can be about different <a>subjects</a>.
  </dd>
  <dt><dfn>data minimization</dfn></dt>
  <dd>
The act of limiting the amount of shared data strictly to the minimum
necessary to successfully accomplish a task or goal.
  </dd>
  <dt><dfn data-lt="decentralized identifiers|DID|DIDs">decentralized identifier</dfn></dt>
  <dd>
A portable URL-based identifier, also known as a <strong><em>DID</em></strong>,
associated with an <a>entity</a>. These identifiers are most often used in a
<a>verifiable credential</a> and are associated with <a>subjects</a> such that a
<a>verifiable credential</a> itself can be easily ported from one
<a>repository</a> to another without the need to reissue the <a>credential</a>.
An example of a DID is <code>did:example:123456abcdef</code>.
  </dd>
  <dt><dfn data-lt="decentralized identifier documents|DID document|DID documents">decentralized identifier document</dfn></dt>
  <dd>
Also referred to as a <strong><em>DID document</em></strong>, this is a document 
that is accessible using a <a>verifiable data registry</a> and contains
information related to a specific <a>decentralized identifier</a>, such as the
associated <a>repository</a> and public key information.
  </dd>
  <dt><dfn data-lt="predicates|derived predicates">derived predicate</dfn></dt>
  <dd>
A verifiable, boolean assertion about the value of another attribute in a
<a>verifiable credential</a>. These are useful in zero-knowledge-proof-style
<a>verifiable presentations</a> because they can limit information disclosure.
For example, if a <a>verifiable credential</a> contains an attribute
for expressing a specific height in centimeters, a derived predicate
might reference the height attribute in the <a>verifiable credential</a>
demonstrating that the <a>issuer</a> attests to a height value meeting the
minimum height requirement, without actually disclosing the specific height
value. For example, the <a>subject</a> is taller than 150 centimeters.
  </dd>
  <dt><dfn>digital signature</dfn></dt>
  <dd>
A mathematical scheme for demonstrating the authenticity of a digital message.
  </dd>
  <dt><dfn data-lt="entities|entity's">entity</dfn></dt>
  <dd>
A thing with distinct and independent existence, such as a person,
organization, or device that performs one or more roles in the ecosystem.
  </dd>
  <dt><dfn data-lt="graphs">graph</dfn></dt>
  <dd>
A network of information composed of <a>subjects</a> and their relationship
to other <a>subjects</a> or data.
  </dd>
  <dt><dfn data-lt="hashlinks|hashlink" data-dfn-type="dfn" id="dfn-hashlinks">hashlink</dfn></dt>
  <dd>
Hashlink URLs can be used to provide content integrity for links to external resources. 
  </dd>
  <dt><dfn data-lt="holders|holder's|holders'">holder</dfn></dt>
  <dd>
A role an <a>entity</a> might perform by possessing one or more
<a>verifiable credentials</a> and generating <a>presentations</a> from them.
A holder is usually, but not always, a <a>subject</a> of the <a>verifiable
credentials</a> they are holding. Holders store their <a>credentials</a> in
<a>credential repositories</a>.
  </dd>
  <dt><dfn data-lt="identities|identity's">identity</dfn></dt>
  <dd>
The means for keeping track of <a>entities</a> across contexts. Digital
identities enable tracking and customization of <a>entity</a> interactions
across digital contexts, typically using identifiers and attributes. Unintended
distribution or use of identity information can compromise privacy. Collection
and use of such information should follow the principle of
<a>data minimization</a>.
  </dd>
  <dt><dfn data-lt="identity providers|idp">identity provider</dfn></dt>
  <dd>
An identity provider, sometimes abbreviated as <em>IdP</em>, is a system
for creating, maintaining, and managing identity information for
<a>holders</a>, while providing authentication services to
relying party applications within a federation or distributed network.
In this case the <a>holder</a> is always the <a>subject</a>. Even if the
<a>verifiable credentials</a> are bearer <a>credentials</a>, it is assumed the
<a>verifiable credentials</a> remain with the <a>subject</a>, and if they are
not, they were stolen by an attacker. This specification does not use this term
unless comparing or mapping the concepts in this document to other
specifications. This specification decouples the <a>identity provider</a>
concept into two distinct concepts: the <a>issuer</a> and the <a>holder</a>.
  </dd>
  <dt><dfn data-lt="issuers|issuer's">issuer</dfn></dt>
  <dd>
A role an <a>entity</a> can perform by asserting <a>claims</a> about one or
more <a>subjects</a>, creating a <a>verifiable credential</a> from these
<a>claims</a>, and transmitting the <a>verifiable credential</a> to a
<a>holder</a>.
  </dd>
  <dt><dfn data-lt="presentations">presentation</dfn></dt>
  <dd>
Data derived from one or more <a>verifiable credentials</a>, issued by one or
more <a>issuers</a>, that is shared with a specific <a>verifier</a>. A
<dfn data-lt="verifiable presentations">verifiable presentation</dfn>
is a tamper-evident presentation encoded in such a way that authorship of the
data can be trusted after a process of cryptographic verification. Certain
types of verifiable presentations might contain data that is synthesized from,
but do not contain, the original <a>verifiable credentials</a> (for example,
zero-knowledge proofs).
  </dd>
  <dt><dfn data-lt="credential repository|credential repositories|repositories">repository</dfn></dt>
  <dd>
A program, such as a storage vault or personal <a>verifiable credential</a>
wallet, that stores and protects access to <a>holders'</a>
<a>verifiable credentials</a>.
  </dd>
  <dt><dfn>selective disclosure</dfn></dt>
  <dd>
The ability of a <a>holder</a> to make fine-grained decisions about what 
information to share.
  </dd>
  <dt><dfn data-lt="subjects|subject's">subject</dfn></dt>
  <dd>
A thing about which <a>claims</a> are made.
  </dd>
  <dt><dfn>user agent</dfn></dt>
  <dd>
A program, such as a browser or other Web client, that mediates the
communication between <a>holders</a>, <a>issuers</a>, and <a>verifiers</a>.
  </dd>
  <dt><dfn data-lt="credential validation">validation</dfn></dt>
  <dd>
The assurance that a <a>verifiable credential</a> or a
<a>verifiable presentation</a> meets the needs of a <a>verifier</a> and other
dependent stakeholders. This specification is constrained to <a>verifying</a>
<a>verifiable credentials</a> and <a>verifiable presentations</a> regardless of
their usage. Validating <a>verifiable credentials</a> or
<a>verifiable presentations</a> is outside the scope of this specification.
  </dd>
  <dt><dfn data-lt="verifiable data registries">verifiable data registry</dfn></dt>
  <dd>
A role a system might perform by mediating the creation and <a>verification</a>
of identifiers, keys, and other relevant data, such as
<a>verifiable credential</a> schemas, revocation registries, issuer public keys,
and so on, which might be required to use <a>verifiable credentials</a>. Some
configurations might require correlatable identifiers for <a>subjects</a>. Some
registries, such as ones for UUIDs and public keys, might just act as namespaces
for identifiers.
  </dd>
  <dt><dfn data-lt="verify|verified|verifying|verifiable|verifiability">verification</dfn></dt>
  <dd>
The evaluation of whether a <a>verifiable credential</a> or <a>verifiable presentation</a> 
is an authentic and timely statement of the issuer or presenter, respectively.  
    This includes checking that: the credential (or presentation) conforms to the specification; the proof method is
satisfied; and, if present, the status is successfully checked.

  </dd>
  <dt><dfn data-lt="verifier|verifiers|verifier's|verifier(s)|credential verifiers|credential verifier's">verifier</dfn></dt>
  <dd>
The <a>entity</a> verifying a claim about a given subject.
  </dd>
  <dt><dfn data-lt="URI|URIs">URI</dfn></dt>
  <dd>
A Uniform Resource Identifier, as defined by [[RFC3986]].
  </dd>
</dl>