Multi-Party Computation (MPC) is important to online societies and economies because it addresses the challenge of unlocking data from multiple parties for shared analysis without ever compromising user privacy regulations.

This capability has many innovative and potentially game-changing uses. It can enable multiple banks to run risk analysis algorithms over the data that they hold collectively, potentially leading to a massive improvement in fraud detection and prevention. It could empower doctors to securely compare an individual’s DNA with a database of cancer patients’ DNA, significantly increasing the chances of identifying whether they are at risk. One potential application could be for nation states and NGO's sharing sensitive logistics capacity information, for use in the coordination of international rescue and relief operations in response to large scale natural disasters.

Until recently however the idea of MPC was more theory than practice. But now thanks to research at the University of Bristol, a host of organisations are developing solutions that are sparking interest from governments and businesses and informing privacy policy debates around the world.

Research leads to a burgeoning sector

The work led by Professor of Cryptology Nigel Smart started in the mid-2000s and focused on developing protocols for both MPC and Fully Homomorphic Encryption that allowed, for the first time, the shared processing of data without revealing it to any of the parties involved.

This breakthrough has directly led to the establishment of several spin-outs and start-ups, such as Cosmian, Duality, Enveil, Galois, Partisia, Sepior, Unbound Security and Zama – all of which use ideas, part of whose genesis can be traced to long term research at Bristol and have collectively attracted over $100m in venture capital investment.

One of these companies, Unbound Security, co-founded by Professor Smart, has subsequently been bought by the global cryptocurrency exchange Coinbase to enable crypto assets to be stored, transferred and deployed more securely.

Another, Galois, has secured $34million in US Government funding and is collaborating with US state departments working on, for example, demonstrating how the US Census Bureau can use MPC technology to carry out micro-economic analysis of trade information without contravening privacy.

Public policy impacts

These advances have also stimulated policy debate in this area. After Galois and Professor Smart provided evidence to the team of Senator Wyden in the US, Senator Wyden led the call for MPC to be used to enable evidenced based policy in areas where the evidence may have privacy issues associated with it. This resulted in two acts of Congress mentioning MPC: The “Right To Know Before You Go Act” of 2017, 2018; and the “Forward Act” of 2018.

The United Nations has also produced guidelines on preserving privacy using MPC; work which the UN team leader said was ‘greatly influenced’ by the University of Bristol.

These developments confirm that the work on MPC protocols, established in Bristol, is helping to significantly alleviate concerns that have previously constrained exploitation of data to inform public policy-making – laying the ground for many more innovations in this area in the years and decades to come.