D2.13 Virtual Persons OBJECTIVE

Objective

The objective of this document is to present a unifying model for identities in the Information Society. This model is driven by typical applications such as identification, authentication, or authorization schemes in relation to rights, duties, obligations and responsibilities. These applications are themselves connected to some of the main issues in our modern society: identities in the digital world and related problems such as profiling of users, identity fraud, single sign-on, universal identifiers, biometrics, etc.

The model presented hereafter is not supposed to be definitive or universal; however, it fits particularly well with the current diversity of these schemes; furthermore, we hope it to be broad enough to evolve and adapt itself when new schemes appear.

We attempt to define the concept of “identity” in the Information Society. We will consider identities of human beings, as well as identities of other entities. In this model, when an identity refers to a human being, it clearly does not refer to the entire person: for example, discussing the existence of a soul for people, animals, or even programs is beyond the scope of this deliverable. It is not our goal to cover all aspects of identity; this would be too ambitious.

We will present a set of unifying concepts based on virtual persons and virtual identities. Virtual identities emphasize the indirection between acting subjects and the identifying information related to their actions and/or the objects supporting these actions. We will use the same set of concepts to model the identity of a physical person, its pseudonyms, or the identity of a legal entity.

Several topics discussed in this paper (authentication, privacy, anonymity, etc.) are studied more thoroughly in other publications, see e.g. Kent & Millett [2004] for the field of authentication and privacy, Bowder and al. [2004] for a discussion of identity, and Pfitzman & Hansen [2006] for the field of anonymity and unlinkability. In contrast to those publications, we focus on the fundamental concepts underlying those fields, i.e., the basic building blocks of identity, identification, and authentication.

The document first introduces virtual persons in an intuitive way, starting with common uses of the concept in Sections and . It is an approach based on examples. The aim is to give the reader the opportunity to get a feeling of the concepts before definitions are introduced in a more formal way.

Sections and of the document visit and illustrate current occurrences of the concepts of virtual person and virtual identity in different fields. Section , on avatars, introduces an important use case for virtual persons. The relation between the players and the avatars (virtual persons) is described from different perspectives. This case will be further investigated, with respect to the model, in Deliverable D17.1. Legal issues related to avatars will be more thoroughly discussed in Deliverable D17.2. Section gives a first illustration of how virtual persons could be used or could intervene in the legal context. This section is based on an article written by Danièle Bourcier in 2001 where she explicitly uses the term “personne virtuelle” in a legal perspective. A deeper study of the possible need to give some new virtual persons a legal status – or even a legal subjectivity – will be carried out in Workpackage 17.

Section of the document gives an intuitive introduction to the model based on virtual persons. It motivates the introduction of two layers to describe more faithfully both the reality of new forms of identities induced by new technologies in the Information Society, and the corresponding privacy issues. It is aimed to be accessible to an audience of non-experts. It describes some limits of current models and motivates the need for a new one. We recommend it to be read before Section which gives a formal description of the model. Section also explains, in a natural way, certain motivations behind the introduction of an abstract layer – the virtual world – in our model.

Section gives a formal description of the model. It is aimed at an audience of experts. It starts with a lexicon of the most important terms (in particular, entity and identity, physical and virtual entities, physical and virtual persons, physical and virtual worlds, subjects, virtual identities) and introduces formal, mathematic-like definitions. It is a refinement of the intuitive approach. In particular, time aspects in the model are studied and described in detail. This section is more abstract than the previous one, but is necessary and valuable in order to reach a scientific definition of the model. This section contains the core information and definitions of the model. The specifications explained in this section will allow a finer description of use-cases and scenarios with the model in Deliverable D17.1.

Section briefly illustrates how to describe virtual persons; pseudonyms are represented in the model, as an example.

Section 7 gives an overall conclusion for the document in relation with Workpackage 17.