Sending Location-Based Keys Using Visible Light Communication

In this thesis we explore the possibilities of using Visible Light Communication (VLC) to build a system that is capable of securely sharing small amounts of data in the form of encryption keys in a boundary defined area. We design and implement the MAC and Physical layers of the system. On the transmission part, the system uses BFSK and Manchester encoding to modulate the signal. The reception is handled in windows of fixed size where the Goertzel algorithm is applied to detect the transmitted frequencies. The transmitters synchronize their transmissions using a simple static scheduling method. Based on this system we then build a secret sharing platform where we utilize Shamir's Secret Sharing protocol. We finally create different scenarios for this platform and test them. Those scenarios include variations of transmitter angles, different kinds of receivers with different sensitivity levels and different heights of the receiver. The results of this research show that the angle of the transmitters and the sensitivity of the receiver are in close relation to how the contours of the reception area would look like. The results also show that the height of the receiver and its sensitivity play a major role of how large this area is