Exclusive key sharing method
US6813357B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 24, 2000 |
| Grant date | Nov 2, 2004 |
| Priority date | — |
| Expiry date | Aug 24, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L9/085
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
In a set-up phase, the base station formulates the secret key S and holds it in secret. The secret information Si which are obtained by dividing the secret key S are distributed in secret to respective terminals 1 to 5 by using cryptographic communication means. In a preparatory phase, the base station 0 broadcasts the preparatory information C1(=gk modp), the exclusive information C2(=y5k modp), the ciphertext C3(=M×K modp), and the particular terminal number 5 to all terminals. In a key sharing phase, the terminal 1 calculates a product of C1{circumflex over ( )}(&lgr;(1, &Lgr;) modq) modp and C2{circumflex over ( )}(&lgr;(5, &Lgr;) modq) modp by using the preparatory information C1 and the exclusive information C2 to obtain K and then calculates M, which are common data to the base station 0, by dividing the ciphertext C3 by K. The terminals 2 to 4 execute similar calculations. As a result, the terminals 1 to 4 can share mutually the common data M.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.