Free-space quantum key distribution (QKD) between prototype handheld devices and a wall mounted terminal (the so-called “quantum ATM”) has been demonstrated by Quantum Communications Hub researchers, based at the University of Bristol, paving the way for short-range consumer QKD. The system under development comprises a miniature transmitter that docks to a larger receiver. The former must be very cheap, so as to add negligible manufacturing cost to the host handheld device, such as a mobile phone. The latter sits in fixed terminals – analogous to ATMs – so is less restricted in size, weight, power consumption and cost. 

The aim of consumer QKD systems is to securely establish quantum keys between a mobile user and an institution, or service provider. These keys then enable consumers to interact with enhanced security over the standard internet, e.g. with financial or health institutions. This same technology could similarly enable ultra-secure sensitive interactions between users and government services, for example, e-voting. With a trusted service provider sharing keys securely with multiple users, the provider can then facilitate shared keys between specific individuals, for personal communications.

Read more about the Hub’s work developing handheld consumer QKD technologies and merging these with quantum-resistant cryptography in the leaflet below.