Hardware Security Modules for Embedded Systems

Being able to trust another IT system that “it always acts as expected” requires consecutive trust into all layers, which are involved in creating a trustworthy IT system. Figure 1 depicts the “pyramid of trust” for a typical IT system, where trust into the whole IT system requires that each layer can rely on the effective security of its underlying layer without being able to verify it directly. This means for instance that a perfect software and hardware security solution could be rendered useless by a weak underlying security system design. Moreover, potential weakness in the system design cannot be detected nor prevented by the upper hardware and software layers.