Cryptographic equipment
US5887064A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 8, 1988 |
| Grant date | Mar 23, 1999 |
| Priority date | — |
| Expiry date | Sep 8, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L9/3234
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
Cryptographic equipment is used with a number of user identification cards which are distributed to various authorized users, each user identification card being a non-volatile memory which can be overwritten in which a user-associated external crypto-ignition key is stored. Insertion of the user identification card in the cryptographic equipment releases the cryptovariable code by cooperation with an internal crypto-ignition key stored internal in a sub-memory of the cryptographic equipment for every authorized user. The cryptovariable required for setting and controlling the cryptosequence generator is stored in encoded form in another sub-memory of the variable memory, and is capable of being decoded with the cryptovariable code.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.