Today, IoT devices represented by smart homes and wearable devices have emerged in an endless stream. The emergence of functional bracelets, functional sockets, sweeping robots, window cleaning robots, and AI voice assistants have greatly enriched people's daily lives. Due to its convenient use and wide application scenarios, the smart door lock has received extensive attention since its launch. Today's smart door locks generally have a variety of unlocking methods, such as fingerprint unlocking, password unlocking, APP unlocking, remote unlocking, without carrying the key, the application experience of one click to open is highly respected by the majority of users. Unlike other IoT devices, door locks are responsible for room access, so security issues have become a top priority for it. A little search on the Internet can get information about security risks such as man-in-the-middle attacks, replay attacks and APP cracks of smart door locks. Smart door lock products need a system base level operation technology and a high level of security to support its wide range of application scenarios. The multi-factor authentication product (MFA) of the Trusfort has many patented technologies such as device fingerprint, soft security space, and device threat awareness. It can effectively identify the uniqueness of mobile devices and the Internet of Things, and protect data security during data transmission with built-in security keys. It can resist multiple intrusion and monitoring methods including replay attacks, man-in-the-middle attacks, data reorganization, and effectively guarantee the security of the IoT device and network communication.