Paper 2014/289

An Empirical Study and some Improvements of the MiniMac Protocol for Secure Computation

Ivan Damgaard and Rasmus Lauritsen, and Tomas Toft

Abstract

Recent developments in Multi-party Computation (MPC) has resulted in very efficient protocols for dishonest majority in the pre- processing model. In particular, two very promising protocols for Boolean circuits have been proposed by Nielsen et al. (nicknamed TinyOT) and by Damg ̊ard and Zakarias (nicknamed MiniMac). While TinyOT has already been implemented, we present in this paper the first implemen- tation of MiniMac, using the same platform as the existing TinyOT im- plementation. We also suggest several improvements of MiniMac, both on the protocol design and implementation level. In particular, we sug- gest a modification of MiniMac that achieves increased parallelism at no extra communication cost. This gives an asymptotic improvement of the original protocol as well as an 8-fold speed-up of our implementation. We compare the resulting protocol to TinyOT for the case of secure com- putation in parallel of a large number of AES encryptions and find that it performs better than results reported so far on TinyOT, on the same hardware.

Note: Added thanks for European Research Council Grant