Starting from the basic theory of dependencies between instructions inside an assembly code, this project aims to exploit them to evaluate firmware reliability. When a piece is produced, it has to be tested to ensure its reliability. Testing, in the case that is considered, means letting execute a "gold" piece (a piece that has been already tested and it can be considered working), extracting from it a register sign depending on every register value at the moment in which the sign is computed and, finally, using the "gold" sign as comparison with all other signs belonging to the pieces to be tested.