CAREER: Privacy Preserving Transactions with Accountability Extensions

George Mason University, Fairfax VA

Investigators

Abstract

The amount of digital data collected and handled electronically is constantly increasing and poses serious threats to user privacy. While a number of cryptographic mechanisms that enhance data privacy exist in the literature, they suffer from prohibitive computational and communication costs and do not offer accountability mechanisms. Without improvements in efficiency and addition of accountability mechanisms, it is unlikely that the so much needed privacy-preserving systems will be massively adopted. Towards the goal of bringing privacy-enhancing technologies closer to adoption, this project defines and constructs a number of new cryptographic building blocks such as new types of digital signatures, cryptographic accumulators and zero-knowledge proofs which are at the core of mechanisms used to enhance privacy. In order to build practical protocols, the project introduces new security relaxations and security models (such as user-device separation) while adhering to the principles of provable secure protocol design, and designs accountability mechanisms for different system participants without relying on trusted third parties and secret trapdoors. The research is organized under three main thrusts which focus on different application areas. Namely, the project investigates anonymous decentralized payments (blockchain based), anonymous authentication (via the use of anonymous credentials), and auditable multi-party computation (MPC) for specific functions. The performed research includes collaborations with Policy and Economics researchers in order to design meaningful accountability mechanisms and leverage blockchain incentives. The project provides education on fundamentals and practices of cryptography and privacy-preserving techniques to students. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.