Protecting states of a cryptographic process using group automorphisms
US8504845B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 30, 2011 |
| Grant date | Aug 6, 2013 |
| Priority date | — |
| Expiry date | Aug 22, 2031 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F21/52
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
In the field of computer enabled cryptography, such as a keyed block cipher having a plurality of rounds, the cipher is hardened against an attack by a protection process which obscures the cipher states and/or the round keys using the properties of group field automorphisms and applying multiplicative masks (instead of conventional XOR masks) to the states of the cipher, for encryption or decryption. This is especially advantageous in a “White Box” environment where an attacker has full access to the cipher algorithm, including the algorithm's internal state during its execution. This method and the associated computing apparatus are useful for protection against known attacks on “White Box” ciphers, by eliminating XOR operations with improved masking techniques and increasing complexity of reverse engineering and of attacks.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.