Concretely efficient secure computation protocols

24.09.2015, 15.00 – 16:00

2015/09/24 15:00-16:30

Speaker: Benny Pinkas | Location: Mornewegstraße 32 (S4|14), Room 3.1.01, Darmstadt

Organizer: Thomas Schneider

Abstract

Protocols for secure computation enable mutually distrustful parties to jointly compute on their private inputs without revealing anything but the final result. Over recent years, secure computation has become practical. A highly important tool in the design of two-party protocols is Yao's garbled circuit construction (Yao 1986). Multiple optimizations on this primitive have led to performance improvements of orders of magnitude, but many of these improvements come at the price of making very strong cryptographic assumptions.

I’ll describe a recent work where we examine whether it is really the case that such strong assumptions are needed. We provide new methods for garbling that are secure solely under the assumption that a function, such as AES, is a pseudorandom function. Our experiments show that in many cases there is very little penalty to not using stronger assumption, and so a more conservative approach to the assumptions being used can be adopted.

The second part of talk will discuss the multi-party setting, where all concretely efficient fully-secure protocols, such as SPDZ, require many rounds of communication. I'll describe a new constant-round MPC protocol that is fully-secure in the presence of malicious adversaries and for any number of corrupted parties. The construction is based on the constant-round BMR protocol of Beaver et al., and is the first fully-secure version of that protocol that makes black-box usage of the underlying primitives, and is therefore concretely efficient. Based on joint work with Shay Gueron, Yehuda Lindell, Ariel Nof, Nigel Smart and Avishay Yanay

Short Bio

Benny Pinkas is an associate professor at Bar Ilan University. He has previously worked in the research labs of Intertrust Technologies, Hewlett-Packard, and Google. His main research areas are cryptography, computer security and privacy, with a focus on secure computation. He has published over 60 highly cited academic publications. He received a starting grant from the ERC, as well as grants from the Israel Science Foundation, the Israel-US Binational research foundation, and the Israel Ministry of Science and Technology, and two European research consortiums