In the pretext of digital lifestyle in a Smart City, home security has become a prudent yet technically challenging area for players of this field. Home access system is a part of home security. In this paper, we present a smart locking and unlocking system for home door security. The proposed system controls the door lock through an Android App using Wi-Fi as the communication protocol, that communicates with WeMos D1 Wi-Fi module embedded in the door lock and the Firebase cloud messaging service. With the help of cloud-based secure messaging service, it is easy to a send a message to a remote Android mobile which belongs to the owner/user of the house. This aspect removes the need to embed GSM module with a smart lock system. To keep vigil of the open/closed status of the door and the unusual events like door smashing, keeping door open for a long time, we use the accelerometer and magnetometer, respectively. The mobile phone App is personalized with a unique user password for the secure access to the door lock system. The system verifies the credentials of the user and then sends an OTP to the mobile App interface using cloud-based secure messaging service. The implementation of the proposed system demonstrates its practicality with minimal accessories. In case of breaching of the secured access, such as, theft or unauthorized opening of the door, the proposed system sends a warning message to the user/owner of the house.