Ensuring trust in cyber space has become an important and indispensable security challenge. Questions about trust in the physical space can be answered based on the factors namely closeness, time, analyzing actions and body language. But in the cyber space these factors are not readily available correctly to ensure and verify trust. Trust can also be established via a third party. But can we know with absolute certainty that the entity with whom we are communicating is trustworthy or not? Cyber security is all about ensuring that software will behave in an expected manner and that it can prevent any threats that deter it from its expected operations. It not just deals with securing networks but rather focuses on ensuring the security of the devices connected to the networks. In this paper, we discuss the approaches used earlier for establishing trust, their limitations and focus on the need for hardware-based root of trust as software-only solutions are inadequate to ensure complete trust. We discuss an emerging technology in the ?eld of trusted computing called the Trusted Platform Module that provides a hardware-based root of trust. We also discuss about its scope, various applications, and the future work being done on it.