MIDEP: Multiparty Identity Establishment Protocol for Decentralized Collaborative Services

Decentralized collaborative architectures are gaining popularity in all application areas, varying from peer-to-peer communication and content management to cloud and ubiquitous services. However, the public identity of the user is still a major concern, in terms of privacy, trace ability, verifiability, masquerading, and other attacks in such environments. We demonstrate two new attacks, identity shadowing and the Man-in-the-Loop (MITL) attacks, which are applicable in particular to multiparty collaborative environments. In this paper, we propose MIDEP, a Multiparty Identity Establishment Protocol for collaborative environments. The proposed protocol allows a client to establish a secure, multiparty, probabilistic, temporal, verifiable, and non-traceable public identity with the collaborating peers in a decentralized architecture. MIDEP allows a client to avoid identity shadowing and protects the service from the resulting threats as well as from colluded information sharing among the collaborating peers. We illustrate how existing collaborative service frameworks can utilize MIDEP to securely establish the public identity prior to beginning the service session. A prototype implementation is utilized to perform extensive experimental analysis. Our results show that MIDEP is highly suitable in terms of overhead to ensure secure identity establishment for underlying decentralized collaborative services.