Method for determining a modular inverse and associated cryptographic processing device
US11029922B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 30, 2019 |
| Grant date | Jun 8, 2021 |
| Priority date | — |
| Expiry date | Sep 16, 2039 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L9/302
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
In a method for determining the modular inverse of a number, successive iterations are applied to two pairs each including a first variable and a second variable, such that at the end of each iteration and for each pair, the product of the second variable and of the number is equal to the first variable modulo a given module. Each iteration includes at least one division by two of the first variable of a first pair or of a second pair, or a combination of the first variable of the first pair and of the first variable of the second pair by addition or subtraction. At least some of the iterations including a combination by addition or subtraction include a step of storing the result of the combination in the first variable of a pair determined randomly from among the first pair and the second pair. An associated cryptographic processing device is also described.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.