Method and device for executing a decrypting mechanism through calculating a standardized modular exponentiation for thwarting timing attacks
US6366673B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 15, 1998 |
| Grant date | Apr 2, 2002 |
| Priority date | — |
| Expiry date | Sep 15, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2207/7261
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
An encrypting exponentiation modulo M is effected by a modular multiplication X*YmodM, where M is a temporally steady but instance-wise non-uniform modulus. The method involves an iterative series of steps. Each step executes one or two first multiplications to produce a first result, and a trim-down reduction of the size of the first result by one or more second multiplications to produce a second result. The method furthermore takes a distinctive measure for keeping the final result of each step below a predetermined multiplicity of the modulus. In particular, the method postpones substantially any subtraction of the modulus as pertaining to the measure to a terminal phase of the modular exponentiation. This is possible through choosing in an appropriate manner one or more parameters figuring in the method. This further maintains overall temporal performance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.