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</dfn></dt>
  <dd>
A set of one or more <a>claims</a> made by an <a>issuer</a>.
The <a>claims</a> in a credential can be about different <a>subjects</a>.
<p>
  Our definition of credential differs from, 
  <a href="https://csrc.nist.gov/glossary/term/credential">NIST's definitions of credential</a>.
</p>
  </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>credential repository</a> to another without the need to reissue the <a>credential</a>.
An example of a DID is `did:example:123456abcdef`.
  </dd>
  <dt><dfn class="lint-ignore" 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>credential repository</a> and public key information.
  </dd>
  <dt><dfn data-lt="default graph">default graph</dfn></dt>
  <dd>
    The <a>graph</a> containing all <a>claims</a> that are not explicitly part of
    a <a>named graph</a>.
  </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 class="lint-ignore">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>
Anything that can be referenced in statements as an abstract or concrete noun.
Entities include but are not limited to people, organizations, physical things,
documents, abstract concepts, fictional characters, and arbitrary text. Any
entity might perform roles in the ecosystem, if it is capable of doing so. Note
that some entities fundamentally cannot take actions, e.g., the string "abc"
cannot issue credentials.
  </dd>
  <dt><dfn data-lt="graphs">graph</dfn></dt>
  <dd>
A set of claims, forming a network of information composed of <a>subjects</a>
and their relationship to other <a>subjects</a> or data. Each <a>claim</a> is
part of a graph; this is either explicit in the case of <a>named graphs</a>, or
implicit for the <a>default graph</a>.
  </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>verifiable presentations</a>
from them. A holder is often, 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 class="lint-ignore"
           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
<a>relying party</a> 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="named graphs">named graph</dfn></dt>
  <dd>
A <a>graph</a> associated with specific properties, such as
`verifiableCredential`. These properties
result in separate <a>graphs</a> that contain all <a>claims</a> defined in the
corresponding JSON objects.
  </dd>
  <dt><dfn data-lt="presentation|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>.
  </dd>
  <dt><dfn data-lt="credential repositories">credential 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 class="lint-ignore">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="claim validation">validation</dfn></dt>
  <dd>
The assurance that a <a>claim</a> from a specific <a>issuer</a> satisfies the
business requirements of a <a>verifier</a> for a particular use. This
specification defines how verifiers verify <a>verifiable credentials</a> and
<a>verifiable presentations</a>.<br/>
It also specifies that <a>verifiers</a> validate claims in <a>verifiable
credentials</a> before relying on them. However, the means for such validation
vary widely and are outside the scope of this specification. It is expected
that <a>verifiers</a> will trust certain <a>issuers</a> for certain claims and
apply their own rules to determine which claims in which <a>credentials</a>
are suitable for use by their systems.
  </dd>
  <dt><dfn data-lt="verifiable credential|verifiable credentials|vc|vcs">verifiable credential</dfn></dt>
  <dd>
A verifiable credential 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.
  </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="verifiable presentation|verifiable presentations|vp|vps">verifiable presentation</dfn></dt>
  <dd>
A verifiable presentation 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="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 current 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 check succeeds. Verification of a credential does not
imply evaluation of the truth of <a>claims</a> encoded in the credential.
  </dd>
  <dt><dfn data-lt="verifier|verifiers|verifier's|credential verifiers|credential verifier's">verifier</dfn></dt>
  <dd>
A role an <a>entity</a> performs by receiving one or more
<a>verifiable credentials</a>, optionally inside a
<a>verifiable presentation</a> for processing. Other specifications might refer
to this concept as a <dfn data-lt="relying parties">relying party</dfn>.
  </dd>
  <dt><dfn data-lt="verification material">verification material</dfn></dt>
  <dd>
    Information that could be a cryptographic public key or any other data 
    used to verify a proof.
  </dd>
  <dt><dfn data-lt="URL|URLs">URL</dfn></dt>
  <dd>
A Uniform Resource Locator, as defined by [[URL]]. URLs can be dereferenced such
that they result in a resource, such as a document. The rules for dereferencing,
or fetching, a URL are defined by the URL [=url/scheme=]. This specification
does not use the term URI or IRI because those terms have been deemed to be
confusing to Web developers.
  </dd>
</dl>