Method and system for diversification of a basic key and for authentication of a thus-diversified key
US4811393A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 9, 1987 |
| Grant date | Mar 7, 1989 |
| Priority date | — |
| Expiry date | Jul 9, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L9/3263
- WIPO fieldIT methods for management
- WIPO sectorElectrical engineering
Abstract
The subject of the invention is a method for diversification of a basic key and for authentication of a thus-diversified key as having been fashioned on the basis of a predetermined basic key, and a system for performing the method. An initializing system calculates a diversified key (Sd) on the basis of a basic key (Sb) processed by a biunique combination transformation (T). The key (Sd) recorded in the memory (M3) of a user card (CU3) is authenticated by an exploitation system (4), which calculates a certificate on the basis of the basic key (Sb), while the card (CU3) calculates a certificate on the basis of its key (Sd). These certificates must be identical, taken into account the properties of the transformation (T). The invention is applicable in particular to the secret keys recorded in memory cards.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.