Financial institutions need to protect transactions, client data and proprietary information. Private payments rely on processing card numbers, which must be encrypted to prevent identity theft. Most financial transactions, small and large, take place electronically, and rely on encryption to shield them from cyber-attacks. All such transactions will be compromised if current encryption can be cracked by quantum computers. The scale of the risk and the time required to replace complex security systems means that the financial services sector should start preparing soon. Even short-term, deploying quantum security in combination with existing encryption methods, will bring advantages, not the least benefits in terms of reassuring customers that long-term security of their data is being taken seriously.

Quantum secure communications systems, mainly in the form of QKD, a mature quantum technology for the secure distribution of encryption keys, that has been already successfully trialled for the secure transmission of sensitive financial transactions, can be delivered over private networks. A potential near-term application, where a QKD network could already be cost effective, could be for payments which are of high value or are time critical. Another application could be in two-factor transaction authentication. QKD could provide multiple one-time ‘passwords’, which could be dispensed in a contactless manner to a mobile device via a ‘quantum ATM’. These can subsequently verify in-person or online transactions, and are safer than passwords or PIN numbers which are frequently copied or stolen. This technology is expected to be ready for commercialisation in the next few years, but would take time to be implemented on a large scale. QKD has already been demonstrated at chip scale, wirelessly, and over fibre networks, paving the way for quantum secured transactions from consumer devices. These technologies may take a decade or more to realise on a widespread practical scale, but they are coming.