Finance prepares to defend itself against quantum attacks

Watch out for Q-Day! In a single day, a quantum attack on one of the big US banks could cost up to $3.3 trillion in damage. Doing the math was Citi, which estimates that the probability of a quantum computer-driven attack ranges between 19 and 34 per cent by 2034, but jumps to between 60 and 82 per cent in the following decade.

This is why finance is moving. Hsbc has used a quantum computer to trade European bonds, improving forecasting effectiveness by up to 34%. But it had already extended quantum-safe protection to its tokenized gold offering. JpMorgan uses quantum security to protect its financial data and blockchain infrastructure, while Wells Fargo has conducted tests in the area of 'quantum key distribution'. A historical pioneer like Barclays has experimented with use cases on clearing and settlement, Goldman Sachs is studying quantum algorithms for pricing, Bbva has developed a pilot project of 'distributed quantum simulation' as a basis for exploring complex financial tasks. In Italia, Intesa Sanpaolo has carried out quantum-safe experiments, while Tim, through its subsidiary Telsy, has provided Sparkasse with a 'future-proof' network based on quantum-resistant cryptography.

Meanwhile, the Bank for International Settlements is not standing still: together with Swift, Banca d'Italia, Banque de France and Bundesbank, it has launched a project to test 'post-quantum' cryptographic tools in an operational payment system. "Protecting financial systems from the potential threat posed by quantum computers requires a proactive and coordinated approach," argues the Bri, noting that the challenges go beyond technical aspects and include awareness, resource allocation, skills development, governance.

Quantum computers are not simply 'faster computers'. Because of their characteristics, centred on superposition of states, entanglement and interference, they excel in solving categories of problems such as optimisation, simulation and large-scale factoring, with which finance is confronted every day. McKinsey estimates at $2 trillion the value that will be generated globally by applications of quantum technologies by 2035. About one third of this value, more than 600 billion, will be realised in the financial sphere.

The fragility of finance starts with security, today based on public key cryptography: a classical supercomputer would need trillions of years to 'crack' today's cryptographic systems, a quantum computer would only need a few days, if not hours. But quantum already poses a threat today, because data intercepted now can be deciphered tomorrow, when quantum hardware will be more mature.