Demo: A Practical Application of Visible Light Communication: Opportunistic Sharing of Encryption Keys

We present a demonstration of Jive (Joint Integration of VLC and Encryption), a novel encryption key sharing framework utilizing the emerging wireless technology Visible Light Communication (VLC). Based on the idea of transmitting data by modulating light, we are able to (1) share a secret key within a constrained physical space and (2) leverage this shared key to communicate encrypted information among co-located mobile devices. In this demonstration, we showcase our complete implementation of Jive: a VLC transmitter and a VLC receiver. Both endpoints are built using off-the-shelf components. The VLC link is used to distribute a randomly generated secret key that can only be "observed" by VLC receivers that are physically in the same space as the transmitter. Each receiver is connected over a serial connection to an Android device; we developed applications for Android that take the key from the VLC receiver and subsequently use the key to encrypt or decrypt application data. Our demo invites participants to create their own encrypted messages in the Android application and interact with the VLC prototype as it transmits encryption keys, thus illustrating our system's ability to bootstrap security among physically co-located devices.