Key generation for advanced encryption standard (AES) Decryption and the like
US7702100B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 20, 2006 |
| Grant date | Apr 20, 2010 |
| Priority date | — |
| Expiry date | Feb 5, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2209/125
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
An apparatus for generating round-key words in accordance with a Rijndael algorithm. In one embodiment of the invention, the apparatus includes (a) a key expansion register block, having a key expansion register adapted to receive a final cipher key of a key expansion schedule in accordance with the Rijndael algorithm; (b) a round constant generator; (c) a first XOR adder adapted to add a first word of the key expansion register to a second word to generate and provide a first sum to the key expansion register block; (d) a transformation block adapted to generate a transformed word based on the first sum and the current round constant over four counts of a first cyclical counter; and (e) a second XOR adder adapted to add the transformed word to the first word of the key expansion register to generate and provide a second sum to the key expansion register block.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.