Key sequence generation for cryptographic operations
US10742394B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 2, 2016 |
| Grant date | Aug 11, 2020 |
| Priority date | — |
| Expiry date | Feb 18, 2037 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2209/24
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
Methods, system and devices are provided that generate a sequence of sub-keys for cryptographic operations from a main key. The main key is operated on only once to generate the sub-keys of the sequence, with a transformation comprising one or more one-way functions. The respective bit values of the sub-keys of the sequence are set using respective bit values of the one or more one-way functions. Advantageously, deriving sub-key bits from respective output bits of one or more one-way functions removes or at least reduces correlations between the main key and the sub-keys, as well as between sub-keys, making it harder or even impossible to recover the main key or other sub-keys from a single sub-key, for example as found using a side-channel attack. At the same time, by using the main key only once (rather than using the main key each time a sub-key is generated), the vulnerability of the main key to a side-channel attack is reduced, because the opportunities for recovering physical information that could lead to the discovery of the main key are reduced. Specific embodiments use parallel or chained execution of sub-functions to generate respective sub-keys. Other specific embodimen…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.