Long Nguyen

Doctoral Student
Oxford University


Separating Two Roles of Hashing in Manual Authentication Protocols

A big challenge in pervasive computing is to create secure communication without a PKI or passwords. A new approach is to build security though human trust and interactions creating a low-bandwidth authentication channel. In this talk, I give a brief analysis of authentication protocols of this type as well as concentrating on my contribution to this area.

I start with some one-way authentication schemes (i.e. Balfanz et al, Pasini-Vaudenay, Mashatan-Stinson, and MANA I of Germann-Mitchel-Nyberg) to demonstrate that these do not optimise the human interactions relative to the obtained level of security. The analysis leads to the significance of the idea "separation of security concerns" under which protocols should be designed to tackle random guesses and search attacks separately. This idea leads me develop a new series of one-way, pairwise and group protocols of this type which are optimal in human interactions. These schemes are all based on the human comparison of a short authentication string, which is the digest of the authenticated information.

This is based on joint work with Prof. Bill Roscoe

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More information about our work, which has appeared in Journal of Information and Computation, Proceedings of FCS-ARSPA 2006, and FCS-ARSPA-WITS 2008, is available at: http://web.comlab.ox.ac.uk/oucl/work/long.nguyen/