Back to the Future: Rethinking Endorsement in Order-Execute Blockchains

A new paper from researchers at multiple Chinese institutions (including Rongji Huang, Shengyun Liu) proposes FlexTender, a framework that rethinks endorsement in order-execute blockchains. Modern permissioned blockchains like ChainMaker require flexible endorsement policies per contract, but existing approaches (like Hyperledger Fabric's execute-order-validate) suffer from high abort rates under contention, especially in DeFi. To avoid refactoring their protocol, the team integrated flexible endorsement directly into the classical order-execute architecture. The key innovation is deterministically removing problematic transactions from an ordered list while preserving censorship resistance and decentralization. FlexTender is built on top of Tendermint BFT and embeds endorsements into consensus without additional messaging overhead in the normal case. Empirical evaluation using an Ethereum USDT workload demonstrates up to 10.6x throughput improvement over an EOV simulation on the same platform. This approach is particularly relevant for DeFi applications needing high concurrency without the penalty of speculative execution failures.