The Internet of Things (IoT) has rapidly become one of the most popular devices across businesses and technology. Referred to as the next industrial revolution, it has transformed the way devices interact with each other, with home automation being the one of the popular fields of IoT. Though IoT can make the devices smarter, it also has a potential to expose these same devices to an attacker, to exploit their vulnerabilities, thus raising a concern for security. This paper deals with the security aspects of one of the popular subsets of home automation systems: smart locks. Smart locks replace the traditional door locks; they can be electronically controlled by mobile devices or the lock manufacturer's remote servers. The current state of art, design, implementation, vulnerabilities and the attacks that can be exploited on these devices are discussed. A solution that addresses the design and architecture of IoT smart lock in providing a better security mechanism is proposed for achieving smarter and secure smart homes. It is shown through experimental analysis that the proposed smart lock system is secure against unauthorized access, replay, and relay attacks.