Value comparison server, value comparison encryption system, and value comparison method
US11184163B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 15, 2019 |
| Grant date | Nov 23, 2021 |
| Priority date | — |
| Expiry date | Mar 26, 2040 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L9/3066
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A value comparison server holds a first secret key and a plurality of tags corresponding to values, each of the plurality of tags is a ciphertext obtained by encrypting each of the values with an additive-homomorphic encryption scheme by using secret keys including the first secret key and a first parameter, a plaintext space has remainder operation with a natural number as modulo in the encryption scheme, and the value comparison server generates a value used for comparing two values corresponding to two tags included in the plurality of tags from the first secret key and the two tags by using the additive homomorphism; and determines which of the two values is greater or equal, on the basis of whether a discrete logarithm of the generated value to the first parameter can be calculated within a value of a predetermined range.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.