Software protection apparatus and the method of protection utilizing read-write memory means having inconsistent input and output data
US5754647A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 27, 1996 |
| Grant date | May 19, 1998 |
| Priority date | — |
| Expiry date | Mar 27, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2221/2109
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An apparatus and method for software protection utilizing a read-write memory device having output data that is inconsistent with the corresponding input data. An emulator detector monitors address inputs to the memory device and detects suspect addressing that indicates an unauthorized memory access is taking place. Upon detection of suspect addressing, the emulator detector switches the memory into a mode in which the memory generates erroneous data, either continuously or intermittently. In addition, the emulator detector can drive a system bus, such as an address bus, a data bus, or a control bus, to a high or low state, either continuously or intermittently, causing an erroneous data read or failure of the emulator system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.