Data processing device with high security of stored programs
US4879645A · kind A · utility
48Cited by
7References
12Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Feb 10, 1988 |
| Grant date | Nov 7, 1989 |
| Priority date | — |
| Expiry date | Feb 10, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2221/2153
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An IC card comprises CPU, PROM for storing programs, and RAM for storing the results of arithmetic operations. PROM stores a table on which the names of specific programs are registered. RAM has execution counters which counts up each time each program is run so that the number of times the specific program is run is memorized. Prior to the running of each program by CPU, it is judged whether or not the program is a specific one. If it is the specific program, the execusion counter counts up. When the count value of the execution counter is above a predetermined value, the running of the specific program is prevented.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.