Ad-hoc key agreement: A brief history and the challenges ahead

Two decades ago, two influential papers on key agreement in ad hoc settings set off a torrent of follow-up research. A decade ago, several players in the consumer-facing ICT industry realized that this research could address a burning problem they faced, also known as the device association problem (sometimes also referred to as the device pairing problem): how to allow ordinary people to securely, yet easily and without additional cost, set up secure communication between their new personal devices. A concerted effort by researchers, practitioners and standards development organizations resulted in device association solutions being widely deployed. In this article, we briefly survey this journey and reflect on the current open problems in security association setup brought forth by the exploding popularity of Internet-of-Things devices.