On the trade-off between communication and trust in secure computations
Piessens, Bart De Decker, Erik Van Hoeymissen and Gregory Neven. At ECOOP
Workshop on Mobile Object Systems, Cannes, France, June 13, 2000.
In this paper, we show that mobile code
technology may prove to be a useful tool in advanced cryptographic protocols
for secure distributed computing.
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 nonrealistic. 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.
We will show in this paper how the use of mobile agents employing these cryptographic
techniques can provide for a tradeoff 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 level of trust needed
in this case is much less than the level of trust needed for a classical trusted