Leak-resistant cryptographic indexed key update
US6539092B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Jul 2, 1999 |
| Grant date | Mar 25, 2003 |
| Priority date | — |
| Expiry date | Jul 2, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2207/7219
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
Methods and apparatuses for increasing the leak-resistance of cryptographic systems using an indexed key update technique are disclosed. In one embodiment, a cryptographic client device maintains a secret key value as part of its state. The client can update its secret value at any time, for example before each transaction, using an update process that makes partial information that might have previously leaked to attackers about the secret no longer usefully describe the new updated secret value. By repeatedly applying the update process, information leaking during cryptographic operations that is collected by attackers rapidly becomes obsolete. Thus, such a system can remain secure (and in some embodiments is provably secure) against attacks involving analysis of measurements of the device's power consumption, electromagnetic characteristics, or other information leaked during transactions. The present invention can be used in connection with a client and server using such a protocol. To perform a transaction with the client, the server obtains the client's current transaction counter. The server then performs a series of operations to determine the sequence of transformations ne…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.