The Research Centre for Blockchain Technology (RCBT) at The Hong Kong Polytechnic University (PolyU) is pleased to share the publication of the Project Aurum Phase 2 report, highlighting the potential of privacy-enhancing technologies (PETs) in enabling digital cash systems that balance user privacy with regulatory compliance.

Led by the Bank for International Settlements (BIS) Innovation Hub Hong Kong Centre, Project Aurum Phase 2 was conducted in collaboration with the Hong Kong Monetary Authority (HKMA), PolyU and the Hong Kong Applied Science and Technology Research Institute (ASTRI).

Prof. Man Ho Allen Au of the Department of Computing and Director of RCBT, together with project team members Dr. Dennis Liu, Edith Yiu and Alven Leung, contributed to the design of the project’s privacy-preserving digital cash architecture, exploring how advanced cryptographic techniques can support privacy protection while meeting regulatory requirements.

The project incorporated PETs, including zero-knowledge proofs (ZKPs), BBS+ signatures and evolving pseudonyms, into a digital cash prototype. These technologies demonstrate how digital cash can provide cash-like privacy while supporting payment integrity, anti-money laundering safeguards and regulatory compliance.

The research highlights how advanced cryptographic techniques can be applied to address real-world challenges in digital finance, contributing to the development of more secure and privacy-preserving digital payment systems.

For more information, please refer to the Project Aurum Phase 2 report