Practical Escrow Protocol for Bitcoin

Abstract

An escrow protocol for Bitcoin allows fair trading using bitcoins. To ensure fairness, the existing proposals made various trade-offs between trust, privacy, and efficiency. In this work, we evaluate the existing escrow protocols for cryptocurrency and propose a practical escrow protocol for Bitcoin that is: (a) computationally efficient; (b) round efficient; and (c) privacy-preserving. The core component of our escrow protocol for Bitcoin is a new verifiably encrypted ECDSA scheme, which may be of independent interest. Furthermore, we implement the escrow protocol for Bitcoin in Bitcoin mainnet, demonstrating the feasibility of our protocol.