Construction symmetric ciphers using the cast design procedure
US5825886A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 5, 1996 |
| Grant date | Oct 20, 1998 |
| Priority date | — |
| Expiry date | Dec 5, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2209/24
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A new design procedure for constructing a family of DES-like Substitution-Permutation Network (SPN) cryptosystems with desirable cryptographic properties including provable resistance to differential cryptanalysis, linear cryptanalysis, and related-key cryptanalysis is described. New cryptosystems called CAST ciphers, constructed according to the procedure, are also described. Details of the design choices in the procedure are given, including those regarding the component substitution boxes (s-boxes), the overall framework, the key schedule, and the round function. A fully specified example CAST cipher, an output of this design procedure, is presented as an aid to understanding the concepts and to encourage detailed analysis by the cryptologic community.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.