Unlock Doors with Your Smartphone’s Fingerprint Reader Using OneTouch

Privacy and security are increasingly serious issues in our modern world, and that fact is encapsulated perfectly in the history of cell phones. Your first cell phone probably didn’t have any kind of security at all — if you had physical access to the phone, then you could utilize all of its functions. Your current smartphone, on the other hand, has all kinds of built-in security. Just to unlock your phone, you can choose between requiring a password, pin code, pattern, fingerprint scan, or facial recognition. OneTouch is a DIY biometric lock that takes advantage of your smartphone’s fingerprint scanner to provide physical security.

Biometric and IoT locks are already common on the consumer market, but a plethora of newsworthy vulnerabilities and hacks should shake your confidence in them. OneTouch has potential attack vectors of its own, but at least it’s fully under your control. Its creator, Shebin Jose Jacob, designed both the OneTouch hardware and the smartphone app to control it. To lock or unlock the electronic deadbolt, you simply open the app and scan your fingerprint. A command will then be sent to the OneTouch device and the position of the deadbolt will be toggled.

The hardware consists of three primary components: the electronic deadbolt, a NodeMCU ESP8266 board, and a relay module that acts as an intermediary between them. Those are housed within a 3D-printed enclosure that was designed in Autodesk Fusion 360 CAD software. The smartphone app was built using the Firebase platform, which provides authentication when sending the lock/unlock command to the ESP8266. That should provide pretty solid security from remote attacks, but it doesn’t do anything for local attacks. If someone can gain access to the OneTouch hardware itself, they’ll be able to open the lock easily. If, however, that isn’t an issue for your use case, you might want to consider this project.