Semi-trusted hosts and mobile agents: enabling secure distributed computations

Ref: Bart De Decker, Frank Piessens, Erik Van Hoeymissen, and Gregory Neven. In E. Horlait, editor, Mobile Agents for Telecommunication Applications, Second International Workshop, MATA 2000, volume 1931 of Lecture Notes in Computer Science, pages 219-232. Springer, 2000.

Abstract: Secure distributed computing addresses the problem of performing a computation with a number of mutually distrustful participants, in such a way that each of the participants has only limited access to the information needed for doing the computation. In the presence of a third party, completely trusted by all participants the problem is trivially solvable. However, this assumption is in many applications non-realistic.

Over the past two decades, a number of solutions requiring no trusted third party have been developed using cryptographic techniques. The disadvantage of these cryptographic solutions is the excessive communication overhead they incur. In this paper, we will show how to overcome these disadvantages and thus enable secure distributed computations in practice.

Our approach uses mobile agents employing these cryptographic techniques to provide for a trade-off between communication overhead and trust. The communication overhead problem would be solved if the communicating parties were brought close enough together. Our solution is to use mobile agents to execute the cryptographic protocols. Of course, a mobile agent needs to trust his execution platform, but we show that the trust requirements in this case are much lower than for a classical trusted third party.