Ninja : Non Identity Based, Privacy Preserving Authentication for Ubiquitous Environments

Most of today's authentication schemes involve verifying the identity of a principal in some way. This process is commonly known as entity authentication. In emerging ubiquitous computing paradigms which are highly dynamic and mobile in nature, entity authentication may not be sufficient or even appropriate, especially if a principal's privacy is to be protected. In order to preserve privacy, other attributes (e.g. location or trustworthiness) of the principal may need to be authenticated to a verifier.