Security system and method for preventing rollback attacks on silicon device firmware
US11216597B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 14, 2020 |
| Grant date | Jan 4, 2022 |
| Priority date | — |
| Expiry date | Jun 4, 2040 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F21/577
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A chip system comprising ROM code including a bootloader which runs whenever the chip is powered on; and programmable fuse array memory storing version identifiers, NVMs in which copies of a version of bootable firmware are stored, wherein a first identifier is stored including active major number and minor numbers, signed with a private key; wherein a second identifier is stored including recovery major and minor numbers, signed with said private key; and hardware which obeys a first command by the boot ROM code to disable until next system reset, writing to the recovery NVM other than to the bootloader, and obeys a second command, to lift write protection of the recovery NVM, wherein firmware images associated with both said versions, and both said identifiers, are signed with said private key, and the boot ROM code authenticates firmware image/s and said identifiers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.