Securing keys of a cipher using properties of the cipher process
US8718280B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 17, 2010 |
| Grant date | May 6, 2014 |
| Priority date | — |
| Expiry date | Oct 29, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2209/16
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
In the field of computer enabled cryptography, such as a block cipher, the cipher is hardened against an attack by protecting the cipher key, by applying to it a predetermined linear permutation before using one key to encrypt or decrypt a message. 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 where the key is derived through a process and so is unknown when the software code embodying the cipher is compiled. This is typically the case where there are many users of the cipher and each has his own key, or where each user session has its own key.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.