| Presentation | 2002/7/12 Discussions on Unconditionally Secure VSS Robust against Dishonest Majority Akira OTSUKA, Junji SHIKATA, Hideki IMAI, |
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| PDF Download Page | PDF download Page Link |
| Abstract(in Japanese) | (See Japanese page) |
| Abstract(in English) | In this paper, we introduce an unconditionally secure verifiable secret sharing scheme that works even if majority of the players are dishonest. We mean by unconditionally secure that the security of the scheme does not depend on any unproven assumptions such as computational ones. We assume that each player including a dealer has a pre-distributed private key, so that each player can verify any share using his or her private key non-interactively and independently from the other players. Therefore, in the reconstruction phase, even if majority of the players are dishonest but at least t players give correct shares, then the secret can be correctly reconstructed, where t is threshold of the underlying secret sharing scheme. Such a pre-distributed private key can be formed if we have Rivest's trusted initializer or if we can execute interactive multi-party computation at some point of time when more than 2/3 of the players can be trusted (or 1/2 if broadcast channel is available). We achieved a VSS scheme with pre-distributed private keys such that privacy of secret is unconditionally hidden from an adversary with unbound computing power with less than t colluders. Simultaneously, even majority of players are dishonest and with unbounded computing power, if there are more than t honest players, then they can reconstruct a consistent secret. |
| Keyword(in Japanese) | (See Japanese page) |
| Keyword(in English) | Verifiable Secret Sharing / Unconditional Security / Trusted Initializer |
| Paper # | ISEC2002-45 |
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| Conference Information | |
| Committee | ISEC |
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| Conference Date | 2002/7/12(1days) |
| Place (in Japanese) | (See Japanese page) |
| Place (in English) | |
| Topics (in Japanese) | (See Japanese page) |
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| Paper Information | |
| Registration To | Information Security (ISEC) |
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| Language | ENG |
| Title (in Japanese) | (See Japanese page) |
| Sub Title (in Japanese) | (See Japanese page) |
| Title (in English) | Discussions on Unconditionally Secure VSS Robust against Dishonest Majority |
| Sub Title (in English) | |
| Keyword(1) | Verifiable Secret Sharing |
| Keyword(2) | Unconditional Security |
| Keyword(3) | Trusted Initializer |
| 1st Author's Name | Akira OTSUKA |
| 1st Author's Affiliation | Institute of Industrial Science, University of Tokyo() |
| 2nd Author's Name | Junji SHIKATA |
| 2nd Author's Affiliation | Dept. of Electrical and Computer Engineering, Yokohama National University |
| 3rd Author's Name | Hideki IMAI |
| 3rd Author's Affiliation | Institute of Industrial Science, University of Tokyo |
| Date | 2002/7/12 |
| Paper # | ISEC2002-45 |
| Volume (vol) | vol.102 |
| Number (no) | 212 |
| Page | pp.pp.- |
| #Pages | 8 |
| Date of Issue | |