Secret sharing system, data distribution apparatus, distributed data transform apparatus, secret sharing method and program
US9432188B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 4, 2013 |
| Grant date | Aug 30, 2016 |
| Priority date | — |
| Expiry date | Jul 4, 2033 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L9/085
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A secret sharing system transforms computational secret shares to homomorphic secret shares. On a data distribution apparatus, a key selector selects K′−1 keys. A pseudorandom number generator generates pseudorandom numbers from the keys. An encryption part generates a ciphertext from information using the pseudorandom numbers. A key division part divides the keys into N shares fg(n) using an arbitrary sharing. A ciphertext division part divides the ciphertext into N shares fc(n) using an arbitrary sharing. When K shares fsj(i) are input into distributed data transform apparatuses, a reconstruction part generates a reconstructed value Uj by reconstructing shares fsj(i) using the secret sharing, and when K shares fc(i) are input, generates the reconstructed value Uj by reconstructing shares fc(i) using the arbitrary sharing. A redivision part divides reconstructed value Uj into N shares fUj(n) using a homomorphic secret sharing. A transformer generates share ga(i) of the information from K′ shares fUj.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.