Unobservable Contracts from Zerocash and Trusted Execution Environments

Adrian Cinal

Paper 2025/1965

Unobservable Contracts from Zerocash and Trusted Execution Environments

Adrian Cinal

, NASK National Research Institute

Abstract

Privacy-oriented cryptocurrencies like Zerocash only support direct payments and not the execution of more complex contracts. Bitcoin and Ethereum, on the other hand, cannot guarantee privacy, and using them for contract execution leaves open questions about fungibility of the proceeds and requires contract designers to take frontrunning countermeasures. This work reconciles the two worlds and develops a practical framework for decentralized execution of complex contracts that (1) is undetectable to the network at large, (2) maintains anonymity of the potentially mutually distrustful counterparties, (3) guarantees fair termination, and (4) is immediately resistant to frontrunning and miner bribery attacks. This is achieved by leveraging the confidentiality and anonymity guarantees of Zerocash and the verifiability and flexibility of trusted execution environments.

Metadata

Available format(s): PDF
Category: Applications
Publication info: Preprint.
Keywords: Fairness Fungibility Privacy coins Trusted execution environments
Contact author(s): adrian cinal @ nask pl
History: 2025-10-22: approved; 2025-10-20: received; See all versions
Short URL: https://ia.cr/2025/1965
License: CC BY

BibTeX

@misc{cryptoeprint:2025/1965,
      author = {Adrian Cinal},
      title = {Unobservable Contracts from Zerocash and Trusted Execution Environments},
      howpublished = {Cryptology {ePrint} Archive, Paper 2025/1965},
      year = {2025},
      url = {https://eprint.iacr.org/2025/1965}
}