What Makes a Change Irreversible?
Reverting a line of code is easy, and most of the time, firmware is backward-compatible. But what if a piece of hardware is specifically designed not to take older firmware, and the only option is to fix it with a new version?
You could argue: Why design the hardware in such a manner? Well, it could be for a myriad of reasons, including a hardware design bug, a security hash algorithm that was a one-way function, or an older firmware bug that’s being fixed in the newer release. It’s easy to update the software behavior if needed, but it’s not possible to change any hardware behavior. So we go to the next best option — mimic software to accept the hardware flaw and invert the operation on the software side.
This article has been indexed from DZone Security Zone
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