terms.html

<p>
This document attempts to communicate the concepts outlined in the
<a>decentralized identifier</a> space by using specialized terms to discuss
specific concepts. This terminology is included below and linked to throughout
the document to aid the reader:
</p>

<dl class="termlist">

  <dt><dfn data-lt="blockchains|blockchain technology">blockchain</dfn></dt>

  <dd>
A specific type of <a>distributed ledger technology</a> (DLT) that stores ledger
entries in blocks of transactions, which are grouped together and hashed into a
cryptographic chain. Because this type of <a>DLT</a> was introduced by
<a href="https://en.wikipedia.org/wiki/Bitcoin">Bitcoin</a>, the term
<em>blockchain</em> is sometimes used to refer specifically to the Bitcoin
ledger.
  </dd>

  <dt><dfn data-lt="decentralized identifiers|DID|DIDs">decentralized identifier</dfn> (DID)</dt>

  <dd>
A globally unique identifier that does not require a centralized registration
authority because it is registered with <a>distributed ledger technology</a>
(DLT) or other form of decentralized network. The generic format of a DID is
defined in this specification. A specific <a>DID scheme</a> is defined in a
<a>DID method</a> specification.
  </dd>

  <dt><dfn>decentralized identity management</dfn></dt>

  <dd>
<a href="https://en.wikipedia.org/wiki/Identity_management">Identity
management</a> based on <a>decentralized identifiers</a>. Decentralized identity
management extends the identifier creation authority beyond the traditional
roots of trust required by
<a href="https://en.wikipedia.org/wiki/X.500">X.500 directory services</a>,
the <a href="https://en.wikipedia.org/wiki/Domain_Name_System">Domain Name System</a>,
and most national identification systems.
  </dd>

  <dt><dfn>decentralized public key infrastructure</dfn> (DPKI)</dt>

  <dd>
Public key infrastructure based on <a>decentralized identifiers</a> and identity
records (for example, <a>DID documents</a>) containing verifiable
<a>public key descriptions</a>.
  </dd>

  <dt><dfn data-lt="did controllers|did controller(s)">DID controller</dfn></dt>

  <dd>
The entity that has the ability to make changes to a <a>DID document</a>.
A <a>DID</a> can have more than one controller. The <a>DID controller(s)</a>
are denoted by the `controller` property on the top level of the <a>DID
document</a>. Note that the <a>DID controller(s)</a> might include the
<a>DID subject</a>.
  </dd>

  <dt><dfn>DID delegate</dfn></dt>

  <dd>
An entity that the <a>DID controller</a> has approved to use cryptographic
material associated with the <a>DID document</a>. For example, a parent
that controls a child's <a>DID document</a> might approve the child
to use their personal device for authentication purposes. In this case, the
child is the <a>DID delegate</a> and their personal device contains
private cryptographic material to enable the child to authenticate as the DID,
but not to add new personal devices without the parent's approval.
  </dd>

  <dt><dfn data-lt="DID documents">DID document</dfn></dt>

  <dd>
A set of data describing the <a>DID subject</a>, including mechanisms, such as
public keys and pseudonymous biometrics, that the <a>DID subject</a> can use to
authenticate itself and prove their association with the <a>DID</a>. A DID
document might also contain other
<a href="https://en.wikipedia.org/wiki/Attribute_(computing)">attributes</a> or
<a href="https://en.wikipedia.org/wiki/Claims-based_identity">claims</a>
describing the subject. These documents are graph-based data structures that
are typically expressed using [[JSON-LD]], but can be expressed using other
compatible graph-based data formats.
  </dd>

  <dt><dfn data-lt="DID fragments">DID fragment</dfn></dt>

  <dd>
The portion of a <a>DID URL</a> that follows the first hash sign character
(<code>#</code>). DID fragment syntax is identical to the URI fragment syntax.
  </dd>

  <dt><dfn data-lt="DID methods">DID method</dfn></dt>

  <dd>
A definition of how a specific <a>DID scheme</a> can be implemented on a
specific <a>distributed ledger</a> or network, including the precise methods by
which <a>DIDs</a> are resolved and deactivated and <a>DID documents</a> are
written and updated.
  </dd>

  <dt><dfn data-lt="DID paths">DID path</dfn></dt>

  <dd>
The portion of a <a>DID URL</a> that begins with and includes the first forward
slash character (<code>/</code>). DID path syntax is identical to the URI path
syntax.
  </dd>

  <dt><dfn data-lt="DID queries">DID query</dfn></dt>

  <dd>
The portion of a <a>DID URL</a> that follows the first question mark character
(<code>?</code>). DID query syntax is identical to the URI query syntax.
  </dd>

  <dt><dfn data-lt="decentralized identifier registry|decentralized identifier registries|DID registries">DID registry</dfn></dt>

  <dd>
A role a system performs to mediate the creation, verification, updating, and
deactivation of <a>decentralized identifiers</a>. A DID registry is a type of
verifiable data registry. For more information, see [[VC-DATA-MODEL]].
  </dd>

  <dt><dfn data-lt="DID resolvers">DID resolver</dfn></dt>

  <dd>
A system that is capable of retrieving a <a>DID document</a> for a given
<a>DID</a>. These systems are specified in the DID Resolution specification
[[DID-RESOLUTION]].
  </dd>

  <dt><dfn data-lt="DID schemes">DID scheme</dfn></dt>

  <dd>
The formal syntax of a <a>decentralized identifier</a>. The generic DID scheme
is defined in this specification. Separate <a>DID method</a> specifications
define a specific DID scheme that works with that specific <a>DID method</a>.
  </dd>

  <dt><dfn data-lt="DID subjects">DID subject</dfn></dt>

  <dd>
The entity the <a>DID document</a> is about. That is, the entity identified by
the <a>DID</a> and described by the <a>DID document</a>.
  </dd>

  <dt><dfn data-lt="DID URLs">DID URL</dfn></dt>

  <dd>
A <a>DID</a> plus an optional <a>DID path</a>, optional <code>?</code> character
followed by a <a>DID query</a>, and optional <code>#</code> character followed
by a <a>DID fragment</a>.
  </dd>

  <dt><dfn data-lt="distributed ledger technology|DLT">distributed ledger</dfn> (DLT)</dt>

  <dd>
A <a href="https://en.wikipedia.org/wiki/Distributed_database">distributed database</a>
in which the various nodes use a
<a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>
to maintain a shared ledger in which each transaction is cryptographically
signed and chained to the previous transaction.
  </dd>

  <dt><dfn data-lt="XDI">extensible data interchange</dfn> (XDI)</dt>

  <dd>
A semantic graph format and semantic data interchange protocol defined by the
<a href="https://www.oasis-open.org/committees/xdi/">OASIS XDI Technical Committee</a>.
  </dd>

  <dt><dfn data-lt="identity owners">identity owner</dfn></dt>

  <dd>
The natural person, party, organization, or thing whose identity is represented
by a <a>DID</a> and who directly controls the private keys to control the
<a>DID document</a>. Note that this specification avoids the term <em>user</em>
since a <a>DID subject</a> is not always an individual person.
  </dd>

  <dt><dfn data-lt="proofPurpose">proof purpose</dfn></dt>

  <dd>
The specific intent for a proof, the reason why an entity created it.
Acts as a safeguard to prevent the proof from being misused for a purpose
other than the one it was intended for.
  </dd>

  <dt><dfn>JSON Pointer</dfn></dt>

  <dd>
Defines a string syntax for identifying a specific value within a JavaScript
Object Notation (JSON) document, as defined in [[RFC6901]].
  </dd>

  <dt><dfn>public key description</dfn></dt>

  <dd>
A JSON object contained inside a <a>DID document</a> that contains all the
metadata necessary to use a public key or verification key.
  </dd>

  <dt><dfn data-lt="resource">resource</dfn></dt>

  <dd>
The term resource is used in the same way as defined for HTTP in [[RFC7231]];
that is, a resource is the target of a request and is identified by a URI.
This specification does not limit the nature of a resource, but defines an
interface that might be used to interact with resources when identified by
a <a>DID</a>.
  </dd>

  <dt><dfn data-lt="service endpoints">service endpoint</dfn></dt>

  <dd>
A network address at which a service operates on behalf of a <a>DID subject</a>.
Examples of specific services include discovery services, social networks, file
storage services, and verifiable claim repository services. Service endpoints
might also be provided by a generalized data interchange protocol, such as
<a>extensible data interchange</a>.
  </dd>

  <dt><dfn data-lt="URI|URIs">Uniform Resource Identifier</dfn> (URI)</dt>

  <dd>
An identifier, as defined by [[RFC3986]].
  </dd>

  <dt><dfn data-lt="">verification method</dfn></dt>

  <dd>
A set of parameters required to independently verify a proof, such
as an identifier for a public/private key pair that would be used in the
proof.
  </dd>
  <dt><dfn data-lt="UUID|UUIDs">Universally Unique Identifier</dfn> (UUID)</dt>

  <dd>
An identifier, as defined by [[RFC4122]].
  </dd>

</dl>