Processor method of multiplying large numbers
US5121431A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 2, 1990 |
| Grant date | Jun 9, 1992 |
| Priority date | — |
| Expiry date | Jul 2, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F7/722
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
For a public key encryption system, for example using the RSA algorithm, large numbers, for example each of the order of 256 bits and represented by a plurality of sequentially stored words, must be multiplied together. To achieve this at high speed there is described a method using a digital signal processor which has two accumulators for accumulating products of words, each accumulator having a capacity of more than twice the size of the words which are multiplied. The two accumulators are used alternately for accumulating partial products of the same significance in a multiplication of two numbers. Pointers to the sequentially stored words are incremented in opposite directions to point to words to be multiplied to form partial products of the same significance, and the pointer incrementing directions are changed for sets of partial products of increasing significance. The pointer control and alternating use of the accumulators enables a significant increase in multiplication speed to be achieved.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.