Resumen
The lack of sufficient guarantee about the authenticity of running smart contracts is a major entry barrier to blockchain networks. By authenticity,we refer to the smart contract ownership or provenance; this implies perfect matching between a published source-code and the corresponding running version of a given smart contract. Block verifiers are services that check the provenance authenticity of the logic contained in blockchain networks. Nevertheless, as a block verifier is an external verification service, it consumes time to use it; and the derived overhead may not comply with temporal requirements of time-sensitive domains like cyber-physical systems. Such systems require that the temporal cost of using external services is assessed prior to the final system deployment. To the best of our knowledge, there are no previous contributions on the determination of the temporal cost of the smart-contract provenance verification process. This paper presents the design and implementation of a middleware that assesses the temporal overhead of accessing the verification services; the middleware is hosted in the global ledger and runs the verification services over large sets of smart contracts. Our contribution is validated by providing an implementation on a real blockchain network, employing actual smart contract verifier logic, and analysing the temporal behavior of the overall system operations to comply with the time-sensitive requirements of cyber-physical systems.