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Publications: Abstract

Secure Multi-Party Computation with Identifiable Abort

Yuval Ishai and Rafail Ostrovsky and Vassilis Zikas

Protocols for secure multi-party computation (MPC) that resist a dishonest majority are susceptible to ``denial of service'' attacks, allowing even a single malicious party to force the protocol to abort. In this work, we initiate a systematic study of the more robust notion of security with identifiable abort}, which leverages the effect of an abort by forcing, upon abort, at least one malicious party to reveal its identity.

We present the first information-theoretic} MPC protocol which is secure with identifiable abort (in short ID-MPC) using a correlated randomness setup. This complements a negative result of Ishai et al. (TCC 2012) which rules out information-theoretic ID-MPC in the OT-hybrid model, thereby showing that pairwise} correlated randomness is insufficient for information-theoretic \mbox{ID-MPC.}

In the standard model (i.e., without a correlated randomness setup), we present the first computationally secure ID-MPC protocol making black-box} use of a standard cryptographic primitive, namely an (adaptively secure) oblivious transfer (OT) protocol. This provides a more efficient alternative to existing ID-MPC protocols, such as the GMW protocol, that make a non-black-box use of the underlying primitives.

As a theoretically interesting sidenote, our black-box ID-MPC provides an example for a natural cryptographic task that can be realized using a black-box access} to an OT protocol but cannot be realized unconditionally using an ideal OT oracle.