IoT and Chain of Trust
In the previous article, we discussed what TPM means and features of TPM. In this short article we'll see applications of TPM in creating and establishing chain of trust. Establishing a tamper proof chain of trust works at two levels. First, a device is booted in a trusted manner. This device interacts with other devices which are also booted in a secure way. The second level deals with establishing "chain of trust" amongst these secure devices. It is important to note that TPM only provides required mechanism to establish root of trust, but it is entirely up to the host machine and software (which includes OS as well as application software) to establish trusted execution environment and should be capable of doing so. Let's see how this mechanism works, with the help of a simple example. Consider a simplistic IoT setup as shown in following figure. The Server At the time of boot, BIOS uses Core Root of Trust i.e. BIOS boot block which is immutable, to...