Zero-Knowledge Smart Contracts

Lead Research Organisation: University of Edinburgh
Department Name: Sch of Informatics

Abstract

This project consists of applying recent advances in non-interactive
zero-knowledge protocols to enhance the privacy of block chain transactions. We
will build on the work presented in ZeroCash, and generalise it to a setting in
which smart contracts are supported. Previous work in this setting achieves
privacy only between either a fixed number of participants, or utilising a
trusted third party.

We will utilize key recent advances that permit the succinct verification of
zero-knowledge computations, zk-SNARKs. We believe that, combined with a
technique for achieving universality (within a time bound), by emulating a
minimalist von Neumann architecture, presented by Ben-Sasson et al., these lay
the groundwork for a private smart-contract system.

We plan to develop a functional proof-of-concept smart contract blockchain, in
which smart contracts may take an arbitrary private input, and produce no
leakage about its value, aside from the output of the contract itself. While
proof-of-concept, the system should be robust and efficient enough for
real-world use. We further intend to demonstrate the security of such a
system, assuming the underlying primitives are secure.

Publications

10 25 50

Studentship Projects

Project Reference Relationship Related To Start End Student Name
EP/N509644/1 01/10/2016 30/09/2021
1929925 Studentship EP/N509644/1 01/09/2017 28/02/2021 Thomas Matthias Kerber
 
Description "Smart contracts" are complex sets of rules governing digital assets, which are enforced by peer verification -- every person can verify the ownership of an asset, for instance, and thereby veto any unauthorized spending. This makes contracts managing private data difficult, as verification may need to access the private data. We show how to utilise cryptography to reduce the requirement for sharing private data, and how to accurately assess what data does need to be revealed in order to perform such verification.
Exploitation Route There are multiple natural extensions of the current research, using the existing model to provide more fine-grained privacy guarantees in various scenarios.
There is practical interest in constructing blockchains with privacy and smart contracts, and this research may be used as the basis for such systems.
Sectors Digital/Communication/Information Technologies (including Software),Financial Services, and Management Consultancy