Method and system for two-stage security code reprogramming
US8572399B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 10, 2007 |
| Grant date | Oct 29, 2013 |
| Priority date | — |
| Expiry date | Oct 21, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N21/4586
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A stored predefined unmodifiable bootable code set may be verified during code reprogramming of a device, and executed as a first stage of code reprogramming of the device. The predefined unmodifiable bootable code set may be stored in a locked memory such as a locked flash memory and may comprise code that enables minimal communication functionality of the device. The predefined unmodifiable bootable code set may be verified using a security algorithm, for example, a SHA-based algorithm. Information necessary for the security algorithm may be stored in a memory, for example, a one-time programmable read-only memory (OTP ROM). The stored information necessary for the security algorithm may comprise a SHA digest, a signature, and/or a key. A second stage code set may be verified and executed during the code reprogramming of the device subsequent to the verification of the stored predefined unmodifiable bootable code set.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.