I. Introduction
Access control to a physical space is defined as the restriction on who, when, where, and in what situation access is allowed. Indoor space is composed of subspaces such as room, entrance, and corridor, all of which are connected by a door. In smart building, each door has a smart lock restricting user entry In other words, the lock is the point where access control policy is enforced. These policies are typically maintained by an entrance management system based on principle of least privilege. In particular, physical security is critical in the physical safety and property of a space; therefore, it must be properly ensured.