Short Paper: Decentralized Fair Exchange for Assets across Blockchain and the Internet

In this brief announcement, we propose a protocol that enables Alice, who holds cryptocurrency assets maintained on a blockchain, and Bob, who holds traditional digital assets on the Internet secured by a trustworthy TLS service, to exchange their assets. The protocol features: (i) Completeness: If both parties are honest, the exchange is guaranteed to be complete;0020(ii) Fairness: Either both Alice and Bob successfully complete the exchange, or neither does; (iii) Decentralization: The protocol operates between two peers without relying on a trusted third party, except for the blockchain and TLS service that are already trusted. To our knowledge, this is the first protocol for peer-to-peer (P2P) fair exchange between blockchain-backed and TLS-backed digital assets that achieves all aforementioned properties.