Optical Wireless authentication for smart devices using an onboard ambient light sensor

As recent smartphone technologies in software and hardware keep on improving, many smartphone users envision to perform various mission critical applications on their smart-phones that were previously accomplished by using PCs. Hence, smartphone authentication has become one of the most critical security issues. Due to the relatively small smartphone form factor, the traditional user id and password typed authentication is considered as an inconvenient and time-taking approach. Taking advantage of various sensor technologies of smartphones, alternative authentication methods such as pattern, gesture, finger print, and face recognition have been actively researched. However, those authentication methods still pose one of speed, reliability, and usability issues. They are especially not suitable for the users in rugged conditions and with physical challenges. In this paper, we evaluate existing alternative smartphone authentication approaches in various usage scenarios to propose ambient light sensor based authentication for smartphones. We have designed and prototyped a challenge-based programmable Fast, Inexpensive, Reliable, and Easy-to-use (FIRE) hardware authentication token. FIRE token uses an onboard LED to transmit passwords via an Optical Wireless Signal (OWS) to the smartphone that captures, and interprets it via its ambient light sensor. FIRE token is a part of the challenge-response technique in the Inverse Dual Signature (IDS) that we designed to facilitate a multi-factor authentication for the mission critical smartphone applications. Our experiments validate that FIRE can authenticate a user on a smartphone in a simple, fast, and reliable way without compromising the security quality and user experience.