Reactive Synthesis of Smart Contract Control Flows. (arXiv:2205.06039v1 [cs.LO])

Smart contracts are small but highly error-prone programs that implement
agreements between multiple parties. We present a reactive synthesis workflow
for the automatic construction of finite-state machines implementing the
control flow of a smart contract. As specification language, we use temporal
stream logic (TSL), which builds on LTL but adds additional mechanisms to
reason about the control flow of infinite data. Our specifications not only
reason about the order of transactions based on guards like access rights, but
also include the updates of fields necessary for a correct control flow. We
show how to comprehensively specify the control flow of various types of common
smart contracts, including auctions, asset transfers, and crowd funding
protocols. Our tool tool implements the approach using BDD-based symbolic
algorithms, resulting in a fast reactive control flow synthesis.