Abstract
The notion of covert security for secure two-party computation serves as a compromise between the traditional semi-honest and malicious security definitions. Roughly, covert security ensures that cheating behavior is detected by the honest party with reasonable probability (say, 1/2). It provides more realistic guarantees than semi-honest security with significantly less overhead than is required by malicious security. The rationale for covert security is that it dissuades cheating by parties that care about their reputation and do not want to risk being caught. But a much stronger disincentive is obtained if the honest party can generate a publicly verifiable certificate when cheating is detected. While the corresponding notion of publicly verifiable covert (PVC) security has been explored, existing PVC protocols are complex and less efficient than the best covert protocols, and have impractically large certificates. We propose a novel PVC protocol that significantly improves on prior work. Our protocol uses only “off-the-shelf” primitives (in particular, it avoids signed oblivious transfer) and, for deterrence factor 1/2, has only 20–40% overhead compared to state-of-the-art semi-honest protocols. Our protocol also has, for the first time, constant-size certificates of cheating (e.g., 354 bytes long at the 128-bit security level). As our protocol offers strong security guarantees with low overhead, we suggest that it is the best choice for many practical applications of secure two-party computation.
| Original language | English (US) |
|---|---|
| Title of host publication | Advances in Cryptology – EUROCRYPT 2019 - 38th Annual International Conference on the Theory and Applications of Cryptographic Techniques, Proceedings |
| Editors | Yuval Ishai, Vincent Rijmen |
| Publisher | Springer Verlag |
| Pages | 97-121 |
| Number of pages | 25 |
| ISBN (Print) | 9783030176587 |
| DOIs | |
| State | Published - 2019 |
| Event | 38th Annual International Conference on the Theory and Applications of Cryptographic Techniques, Eurocrypt 2019 - Darmstadt, Germany Duration: May 19 2019 → May 23 2019 |
Publication series
| Name | Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) |
|---|---|
| Volume | 11478 LNCS |
| ISSN (Print) | 0302-9743 |
| ISSN (Electronic) | 1611-3349 |
Conference
| Conference | 38th Annual International Conference on the Theory and Applications of Cryptographic Techniques, Eurocrypt 2019 |
|---|---|
| Country/Territory | Germany |
| City | Darmstadt |
| Period | 5/19/19 → 5/23/19 |
Funding
As our protocol offers strong security guarantees with low overhead, J. Katz—Work supported in part by a grant from Alibaba. V. Kolesnikov—Work supported in part by Sandia National Laboratories, a multi-mission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energys National Nuclear Security Administration under contract DE-NA-0003525. V. Kolesnikov—Work supported in part by Sandia National Laboratories, a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of EnergysNational Nuclear Security Administration under contract DE-NA-0003525.
ASJC Scopus subject areas
- Theoretical Computer Science
- General Computer Science