Integrity of on demand code decryption
US11244075B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 29, 2017 |
| Grant date | Feb 8, 2022 |
| Priority date | — |
| Expiry date | Sep 11, 2038 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2221/2123
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A system and a method for monitoring the integrity of code are provided. Dummy code is provided in an on demand decryption area of an object file while runtime code is provided elsewhere (and may be in the same object file or another object file). A compensation area is also provided which is initially blank. During execution, checksums can be calculated based on the result of an exclusive or (XOR) operation between contents of the on demand code decryption area and a compensation area such as a compensation area. As the runtime code populates the on demand code decryption area with the runtime code (potentially with the exception of areas masked to maintain integrity of relocation instructions allowed to remain in the dummy code) the compensation area is populated with the result of an XOR operation between the dummy code and the runtime code. As a result, the checksums will be the same throughout execution as long as integrity of the code has not been compromised.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.