Method and apparatus for performing hashing operations using Galois field multiplication
US4538240A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 30, 1982 |
| Grant date | Aug 27, 1985 |
| Priority date | — |
| Expiry date | Dec 30, 2002 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F16/9014
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
The invention comprises a method and apparatus for performing a hashing operation on an N bit number under control of a prespecified N bit hashing constant which comprises performing N/K finite field partial multiplications of the object to be hashed by the hashing constant, utilizing K logic and combinatorial circuits all of which operate in parallel to completely evaluate the number in N/K operations. Another feature of the present invention is that the hashing constant loaded into the system may be changed at will with a resultant changing of the hashing characteristics to suit a particular class of objects to be hashed. This is done by a "select" operation. In the "select" operation, the hashing constant is sequentially loaded into said K logic and combinatorial circuits, each of which comprises a feedback shift register (FSR), said feedback shift registers being so configured that at the end of K operational sequences each of said feedback shift registers contains said hashing constant shifted and permuted in accordance with the particular feedback configuration of said register, a number of bits proportional to its location in the sequence of feedback shift registers, such th…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.