Within the next few years, the number of devices connected to each other and the Internet will outnumber humans by almost five to one. These connected devices will underpin everything from healthcare to transport to energy and manufacturing. This growth is not just in the number or variety of devices, but also in the ways they communicate and share information with each other, building hyper-connected cyber-physical infrastructures that span most aspects of people's lives.<br><br>To maximise the socioeconomic benefits from this revolutionary change, we need to address the myriad trust, identity, privacy, and security issues raised by such large, interconnected infrastructures. Solutions to many of these issues have previously only been developed and tested on systems orders of magnitude less complex in the hope they would 'scale up'. However, the rapid development and implementation of hyper-connected infrastructures means that we need to address these challenges at scale since the issues and the complexity only become apparent when all the different elements are in place.