Cryptography circuit protected against observation attacks, in particular of a high order
US8615079B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 18, 2010 |
| Grant date | Dec 24, 2013 |
| Priority date | — |
| Expiry date | Oct 31, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2209/12
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A cryptography circuit protected against observation attacks comprises at least one register R providing a variable x masked by the mask m, the masked variable being encrypted by a first substitution box S -in a cyclic manner. The circuit also comprises a mask register M delivering at each cycle a mask mt, the transformation of m, the mask m being extracted from mt before being encrypted by a second substitution box S′, the new mask m′ obtained on output from this box S′ is transformed into a mask m′t before being stored in the mask register M. The transformation consists of a bijection or a composition law making it possible to reduce or indeed to cancel any high-order attack in accordance with a model of activity of the registers R and M. Cryptography circuits are protected against high-order observation attacks on installations based on masking.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.