Method and apparatus for a symmetric block cipher using multiple stages
US6185304A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 23, 1998 |
| Grant date | Feb 6, 2001 |
| Priority date | — |
| Expiry date | Feb 23, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2209/24
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
The present invention provides a technique, system, and computer program for a symmetric key block cipher. Variable block sizes and key sizes are supported, as well as a variable number of rounds. The cipher uses multiple stages of processing, where the stages have different structures and different subround functions, to provide excellent resistance to both linear and differential attacks. Feistel Type-3 networks are used, with different networks during different stages. The number of rounds may vary among stages. Subkeys are used in some, but not all, stages. The variable-length keys can be precomputed. A novel manner of using multiplication in a cipher is defined.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.