Flexible Fair and Collusion Resistant Pseudonym
Providing System
Belal Amro1, Albert
Levi2, and Yucel Saygin2
1College of IT, Hebron University,
Palestine
2Faculty of Engineering and
Natural Sciences, Sabanci University, Turkey
Abstract: In service providing systems, user authentication is
required for different purposes such as billing, restricting unauthorized
access, etc., to protect the privacy of users, their real identities should not
be linked to the services that they use during authentication. A good solution
is to use pseudonyms as temporary identities. On the other hand, it may also be
required to have a backdoor in
pseudonym systems for identity revealing that can be used by law enforcement
agencies for legal reasons. Existing systems that retain a backdoor are either
punitive (full user anonymity is revealed), or they are restrictive by
revealing only current pseudonym identity of. In addition to that, existing
systems are designed for a particular service and may not fit into others. In
this paper, we address this gap and we propose a novel pseudonym providing and
management system. Our system is flexible and can be tuned to fit into services
for different service providers. The system is privacy-preserving and
guarantees a level of anonymity for a particular number of users. Trust in our
system is distributed among all system entities instead of centralizing it into
a single trusted third party. More importantly, our system is highly resistant
to collusions among the trusted entities. Our system also has the ability to
reveal user identity fairly in case of a request by law enforcement. Analytical
and simulation based performance evaluation showed that Collusion Resistant
Pseudonym Providing System (CoRPPS) provides high level of anonymity with
strong resistance against collusion attacks.
Keywords: Security, privacy, pseudonym, anonymity,
access control.