Paper 2017/1093

Proposal for Protocol on a Quorum Blockchain with Zero Knowledge

Thomas Espel, Laurent Katz, and Guillaume Robin

Abstract

In this paper, we present an implementation scheme of an RTGS on Quorum using the Solidity language. It is heavily inspired by the Schnorr signature protocol to verify the identity of the participants. We have implemented a distributed ledger solution for Delivery vs Payment that promises to offer increased efficiency and resilience. Our architecture mimics current market structure. For such needs, we added an extra layer of security that allows our solution to comply with the requirements of the regulator while enabling competitive actors to collaborate using the shared registry. It also leaves room for regulation, while still running in a decentralised way with coordinating agents. We use non-interactive zero-knowledge algorithms, which are cryptographic protocols with numerous applications in the fields of cryptocurrencies. They allow an agent to verify that another agent holds a specific information, while the latter never discloses this information. For the sake of our experimentations, we had to use very small integers in our protocols. These integers are too small to comply with current security standards in finance, although the architectural principles can be easily transposed with better performing protocols. We present suggestions to improve our proof of concept and our architecture in the last part.

Note: Updated version of the draft.