Identity Attributes


Identity Attributes are Identifiers or attributes or properties of an Entity (or Digital Identity or even a Digital Subject) that provide Identification of the entity

Identity Attributes should be Attributes that within the current context can be used to separate the entity from the Anonymity Set (Identification) a specific Digital Identity. Otherwise, they are just Attributes.


The Natural Person (i.e. Entity) Bob Smith might be represented as a Digital Subject in the Context of his employer, the Port Control Authority. This Digital Subject might have the following types of Identity Attributes (and associated values) in this context:[1]

This same Entity Bob Smith is also represented as a Digital Identity in a "customer-to-Clothes-R-Us" Context (this customer's relationship with the Clothes-R-Us merchant. In this Context Bob has these Attributes:

However, if we use Identity Correlation of preferredColor and shirtSize and streetNumber and Last Name we may have only one Digital Identity in the result. In some Contexts these attributes may be considered Identity Attributes (HIPAA's Protected Health Information)

In Higgins[2]#


In Higgins a Identity Attributes is identified by a URI that defines its type. The URI
might indicate an Identity Attribute that represented a person's Last Name. The schema associated with the containing Context provides metadata about this URI.


  • An Identity Attributes may have zero or more values
  • The values may be literal types (defined by the XML Schema literal types) or complex (structured) values
  • A special kind of Identity Attributes is called a Subject Relationship whose value is a reference to another Digital Subject in the same or a different Context
  • Some Identity Attributes are defined by the containing Context's schema to allow multiple unique values. For example the attribute preferredBreakfast
    • might have the values {spam, eggs},
    • but it could not have the values {spam, spam, spam, eggs, spam}.

More Information#

There might be more information for this subject on one of the following: