ODYSSEY: Reestablishing Confidentiality in Confidential Blockchain via Delegated Execution
This work addresses execution inference and replay attacks in consortium blockchains arising from side-channel leaks and state continuity within Trusted Execution Environments (TEEs). To mitigate these threats, the authors propose a delegated execution model wherein clients entrust transaction execution to a designated node while other nodes merely synchronize the resulting outputs. This architecture integrates location-aware concurrent execution with a robust delegation failure handling mechanism, significantly reducing the attack surface and preserving transaction confidentiality without compromising performance. A prototype implementation built on FISCO BCOS achieves approximately 4,000 transactions per second (TPS) throughput with latencies as low as 0.4–0.5 seconds in a three-node wide-area network deployment.