Abstract | ||
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The covert security model Aumann and Lindell, TCC 2007 offers an important security/efficiency trade-off: a covert player may arbitrarily cheat, but is caught with a certain fixed probability. This permits more efficient protocols than the malicious setting while still giving meaningful security guarantees. However, one drawback is that cheating cannot be proven to a third party, which prevents the use of covert protocols in many practical settings. Recently, Asharov and Orlandi ASIACRYPT 2012 enhanced the covert model by allowing the honest player to generate a proof of cheating, checkable by any third party. Their model, which we call the PVC publicly verifiable covert model, offers a very compelling trade-off. Asharov and Orlandi AO propose a practical protocol in the PVC model, which, however, relies on a specific expensive oblivious transfer OT protocol incompatible with OT extension. In this work, we improve the performance of the PVC model by constructing a PVC-compatible OT extension as well as making several practical improvements to the AO protocol. As compared to the state-of-the-art OT extension-based two-party covert protocol, our PVC protocol adds relatively little: four signatures and an $$\\approx 67\\,\\%$$ wider OT extension matrix. This is a significant improvement over the AO protocol, which requires public-key-based OTs per input bit. We present detailed estimates showing up﾿to orders of magnitude concrete performance improvements over the AO protocol and a recent malicious protocol. |
Year | DOI | Venue |
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2015 | 10.1007/978-3-662-48800-3_9 | IACR Cryptology ePrint Archive |
Keywords | Field | DocType |
Secure computation,Publicly verifiable covert security | Drawback,Secure multi-party computation,Approx,Computer science,Computer security,Covert,Verifiable secret sharing,Cheating,Computer security model,Oblivious transfer | Journal |
Volume | ISSN | Citations |
2015 | 0302-9743 | 2 |
PageRank | References | Authors |
0.36 | 10 | 2 |
Name | Order | Citations | PageRank |
---|---|---|---|
Vladimir Kolesnikov | 1 | 272 | 12.09 |
Alex J. Malozemoff | 2 | 158 | 8.98 |