D2.13: Virtual Persons and Identities

D2.13 Virtual Persons LEXICON OF THE MAIN DEFINITIONS

A 

Abstract Personabstract person is a synonym for a virtual person.

E 

Entityentity is anything that has a distinct existence; it is the fundamental “thing” that can be identified.

* Digital entitydigital entity is any entity which primarily exists in some digital context, e.g., as a digitally encoded information or as a running computer program.

* Legal entitylegal entity is any entity which has some sort of legal subjectivity, or which is legally recognized in a judicial system.

* Physical entityphysical entity is an entity for which some sort of physical constituent is compulsory.

* Virtual entityvirtual entity is an entity which is or has been the product of the mind or imagination.

I 

Identifying informationIdentifying information is any information which characterizes exactly one entity within a specific context or environment.,

* (Full) identifierfull identifier (or simply identifier), is equivalent to identifying information.

* Partial identifierA partial identifier (or partially identifying information) is any information which characterizes at least one entity within a specific context or environment.

Identity An identity of an entity – according to an observer – is identifying information that can be linked to this entity by that observer.

* Partial identitypartial identity of an entity – according to an observer – is partially identifying information (a partial identifier) that can be linked to this entity by that observer.

Identity-related InformationIdentity-related information is any information that characterizes an entity.

L 

Linklink between two entities, if one entity represents the other one.

(characterization) link between some identity-related information and an entity if this information characterizes this entity.

P 

Physical PersonA physical person is the legally living body of a human being.

S 

Subjectsubject of this virtual person.

V 

Virtual PersonA virtual person is a virtual entity that can have rights, duties, obligations and/or responsibilities associated to it in a certain context.

A virtual person is like a mask for a subject or another virtual person.

It is a synonym for an abstract person.

Virtual Identityvirtual identity, for a given entity, is the identity of a virtual entity linked to this given entity.,

W 

Worldworld is a time-dependant collection of existing entities.

* Physical worldphysical world at a specific point in time, is the collection of all existing physical entities at that specific point in time.

* Virtual worldvirtual world at a specific point in time, is the collection of all existing virtual entities at that specific point in time.

The basic conceptual elements of the proposed model are called “entities”. An entity is anything that has a distinct existence; it is the fundamental “thing” that can be identified.

What is an identity? What is the identity of an entity? Our goal is not to cover all aspects of identity; this would be too ambitious. We consciously restrict our view to the Information Society. Even in this restricted context, the question remains difficult to answer as illustrated by the rich number of attempts to define identity in the specialized literature. We can read, for example,

1. An identity is any subset of attributes of an individual which sufficiently identifies this individual within any set of individuals, in the document coordinated by Pfitzmann and Hansen.

2. The total list of attribute values associated with an entity within a context that provides recognition to the entity in that specific context in recent ISO working documents.

3.  A “name”, or identity, is a set of information that distinguishes a specific entity from every other within a particular environment in the Encyclopedia of Cryptography and Security.

The ITU-T has even compiled several scientific definitions of “identity”: 

1. The properties of an entity that allows it to be distinguished from other entities.

2. The attributes by which an entity is described, recognized or known.

3. The essence of an entity and often described by its characteristics.

4. The fundamental concept of uniquely identifying an object (person, computer, etc.) within a context. That context might be local (within a department), corporate (within an enterprise), national (within the bounds of a country), global (all such object instances on the planet), and possibly universal (extensible to environments not yet known). Many identities exist for local, corporate, and national domains. Some globally unique identifiers exist for technical environments, often computer-generated.

5. Etc…

“Identity” is closely related to “identification” and to what can be identified. We introduce the concept of entity to describe the fundamental “thing” that can be identified. Our definition of “identity” applies not only to persons but explicitly to any entity. This becomes especially relevant with the emergence of the Internet of things. Both physical and virtual entities will be identifiable.

As we will see, our definition of “identity” is very close to the one given by Pfitzmann and Hansen, but it is not equivalent. Actually, it is even closer to Carlisle Adams’ definition.

The term “identifier” has many, sometimes non-converging, definitions in the scientific literature; we introduce the concept of “identifying information” in order to avoid possible confusion. In our model, “identifier” and “full identifier” are equivalent to “identifying information”. Our concept of identity is based on “identifying information”: the main component of an identity is identifying information. However, we make a clear distinction between “identifying information” and “identity”.

“Identifying information” is any information which characterizes exactly one entity within a specific context or environment., “Partially identifying information” is any information which characterizes at least one entity within a specific context or environment.

Examples: 

1. Names, fingerprints, social security numbers, role-pseudonyms are typical examples of identifying information.

2. “John” can be identifying information within the context of a family, but is only partially identifying information with respect to the population of the EU.

Identifying information becomes an “identity” of an entity, according to an observer, if it can be linked to this entity by that observer. In other words, the identifying information becomes an identity, according to an observer, if the existing link between the entity and the identifying information is visible to this observer.

In order to illustrate the difference between identifying information and an identity, we consider, as an example, the fingerprints of a specific individual. These fingerprints might be an identity of this individual from the point of view of the police (who can link this identifying information to this individual when it finds a match in its database), but remain identifying information only (an information known to be very discriminant) according to most other observers. On the contrary, Pfitzmann and Hansen’s definition would consider fingerprints as an identity in both cases, independently from the ability to link this information to a specific individual. 

Note that our definition of “identity” covers in particular

1. “my identity” from the point of view of others (the me) and

2. “my identity” from my own point of view (the I).

Indeed, in the definition, nothing prevents the observer to be the entity itself. 

When the entity is a group, identifying information of the group is partially identifying information (a partial identifier) of each member of the group. In other words, the concept of “group identity” is also covered by our definitions.