Computer systems to inhibit unauthorized copying, unauthorized usage, and automated cracking of protected software
US4558176A · kind A · utility
Inventors
Key dates
| Filing date | Sep 20, 1982 |
| Grant date | Dec 10, 1985 |
| Priority date | — |
| Expiry date | Sep 20, 2002 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2221/2107
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method and apparatus are provided for inhibiting unauthorized copying, unauthorized usage and automated cracking of proprietary software used in computer systems. The computer systems execute protected programs, which are protected by encapsulation and/or encryption. To provide security against unauthorized copying of software, means are provided that detect and inhibit automated cracking of protected programs. These means will destroy or make inaccessible information in the CPU during conditions when automated cracking could occur. These means will also store interrupt contexts in secret to prevent implementation of automated cracking. Additional features may be provided to allow operation as a general purpose computer system, where protected programs are distributed using public key cryptography and a means is provided to convert from this distribution form to the protected execution form.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.