Implementation of a switch-box using a subfield method
US7532721B2 · kind B2 · utility
1Cited by
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26Claims
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Key dates
| Filing date | Oct 28, 2004 |
| Grant date | May 12, 2009 |
| Priority date | — |
| Expiry date | Mar 11, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L9/0631
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
Methods and systems for implementing a switch box (S-box) in a cryptographic application are described. An input to the S-box is converted from a Galois field representation GF(N2) to a Galois subfield representation GF(N)2. The input is converted using a generating polynomial of the form x2+Ax+B, where A and B are elements in GF(N) and where A has a value other than unity. The multiplicative inverse of the Galois subfield representation GF(N)2 is determined. The multiplicative inverse is converted back to the Galois field representation GF(N2). An affine transformation of the multiplicative inverse is then performed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.