Practical Witness-Key-Agreement for Blockchain-based Dark Pools Financial Trading

Ngo, Chan Nam; Massacci, Fabio; Kerschbaum, Florian; Williams, Julian

Abstract

We introduce a new cryptographic scheme, Witness Key Agreement (WKA), that allows a party to securely agree on a secret key with a counter party holding publicly committed information only if the counter party also owns a secret witness in a desired (arithmetic) relation with the committed information. Our motivating applications are over-the-counter (OTC) markets and dark pools, popular trading mechanisms. In such pools investors wish to communicate only to trading partners whose transaction conditions and asset holdings satisfy some constraints. The investor must establish a secure, authenticated channel with eligible traders where the latter committed information matches a desired relation. At the same time traders should be able to show eligibility while keeping their financial information secret. We construct a WKA scheme for languages of statements proven in the designated-verifier Succinct Zero-Knowledge Non-Interactive Argument of Knowledge Proof System (zk-SNARK). We illustrate the practical feasibility of our construction with some arithmetic circuits of practical interest by using data from US$ denominated corporate securities traded on Bloomberg Tradebook.

Citation

Ngo, C. N., Massacci, F., Kerschbaum, F., & Williams, J. (2021). Practical Witness-Key-Agreement for Blockchain-based Dark Pools Financial Trading. In N. Borisov, & C. Diaz (Eds.), Financial Cryptography and Data Security 25th International Conference, FC 2021, Virtual Event, March 1–5, 2021, Revised Selected Papers, Part II (579-598). Springer Verlag. https://doi.org/10.1007/978-3-662-64331-0_30

• Online Publication Date: Oct 23, 2021
• Publication Date: 2021
• Deposit Date: Feb 2, 2021
• Publicly Available Date: Feb 4, 2021
• Publisher: Springer Verlag
• Pages: 579-598
• Series Title: Lecture Notes in Computer Science
• Series Number: 12675
• Book Title: Financial Cryptography and Data Security 25th International Conference, FC 2021, Virtual Event, March 1–5, 2021, Revised Selected Papers, Part II
• ISBN: 978-3-662-64330-3
• DOI: https://doi.org/10.1007/978-3-662-64331-0_30
• Public URL: https://durham-repository.worktribe.com/output/1649186
• Contract Date: Jan 25, 2021