Clock frequency modulation for secure microprocessors
US5404402A · kind A · utility
59Cited by
3References
18Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Dec 21, 1993 |
| Grant date | Apr 4, 1995 |
| Priority date | — |
| Expiry date | Dec 21, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2209/08
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A secure microprocessor is provided with reduced vulnerability to attack. In the past, the secure operation of such processors has been overcome by observing the behavior of the clock used by the processor. Such observations, and the prediction of subsequent clock pulses therefrom, are prevented by modulating the clock by a substantially random function to provide an unpredictable stream of clock pulses. The secure processor is responsive to the unpredictable stream of clock pulses for processing data in accordance with a security algorithm.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.