Method and arrangement for controlling access to EEPROMs and a corresponding computer software product and a corresponding computer-readable storage medium
US6814297B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 16, 2002 |
| Grant date | Nov 9, 2004 |
| Priority date | — |
| Expiry date | Dec 16, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C16/22
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
The invention relates to a method and an arrangement for controlling access to EEPROMs' and to a corresponding computer software product and a corresponding computer-readable storage medium, which can in particular be used to prevent the unauthorized manipulation of EEPROMs. Specifically, it is possible by using the invention to stop the unauthorized use of totally erased EEPROMs on smart-card controllers.EEPROM fuses that, depending on the application, comprise one or more bits, are used in the continuing course of operation of a controller, to permit or forbid security-related functions. Provision is made as part of the invention for EEPROM fuses to be used to permit writing to the EEPROM only if said fuse comprises a given combination of bits. Any manipulation of this fuse, such as by erasing the entire matrix for example or else by manipulating the booting process, then bars all further write accesses to the EEPROM. Similarly, a chip card where the user erases the entire EEPROM in the event of an attack being detected is automatically barred in this way against any further writing operations.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.