SigVM: enabling event-driven execution for truly decentralized smart contracts

This paper presents SigVM, a novel blockchain virtual machine that supports an event-driven execution model, enabling developers to build truly decentralized smart contracts. Under traditional blockchain virtual machine such as Ethereum, the events have to be monitored uninterruptedly and the corresponding function in Smart Contract should be called manually by users once acquiring events. Under SigVM, contracts can emit signal events, on which other contracts can listen. Once an event is triggered, corresponding handler functions are automatically executed as signal transactions.

We build an end-to-end blockchain platform SigChain and a contract language compiler SigSolid to realize the potential of SigVM. Experimental results show that our benchmark applications can be reimplemented with SigVM in an autonomous way, eliminating the dependency on unreliable mechanisms like off-chain relay servers. The development effort of reimplementing these contracts with SigVM is small, i.e., we modified on average 2.6% of the contract code.