MERCAT: Mediated, Encrypted, Reversible, SeCure Asset Transfers

Abstract

For security token adoption by financial institutions and industry players on the blockchain, there is a need for a secure asset management protocol that enables condential asset issuance and transfers by concealing from the public the transfer amounts and asset types, while on a public blockchain. Flexibly supporting arbitrary restrictions on financial transactions, only some of which need to be supported by zero-knowledge proofs. This paper proposes leveraging a hybrid design approach, by using zero-knowledge proofs, supported by restrictions enforced by trusted mediators. As part of our protocol, we also describe a novel transaction ordering mechanism that can support a flexible transaction workflow without putting any timing constraints on when the transactions should be generated by the users or processed by the network validators. This technique is likely to be of independent interest