Cryptographic process execution protecting an input value against attacks
US8605894B2 · kind B2 · utility
1Cited by
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24Claims
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Key dates
| Filing date | Oct 12, 2011 |
| Grant date | Dec 10, 2013 |
| Priority date | — |
| Expiry date | Mar 7, 2032 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2209/16
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A cryptographic process (such as the AES cipher) which uses table look up operations (TLUs) is hardened against reverse engineering attacks intended to recover the table contents and thereby the cipher key. This hardening involves removing any one-to-one correspondence between the TLU inputs and outputs, by altering the output of the TLU dynamically, e.g. at each execution (call) of the TLU. This is done by increasing the size of the tables, applying a dynamically determined mask value to the table input and/or output, or using an inverse of the table.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.