VelogCPS: A safe blockchain network for cyber–physical systems leveraging block verifiers

Non-functional requirements related to safety, security, and timeliness have made cyber–physical systems (CPS) initially reluctant to their integration with blockchain technology. Despite the multiple advantages of blockchain like improved data security and traceability, the main reasons that have slowed down its adoption in CPS still remain. Examples of these are the inherent overhead of accessing the distributed ledger and the security incidents that a number of blockchain networks have suffered since its inception. This paper presents VelogCPS, a novel middleware that guarantees that logic and data managed by blockchain networks of cyber–physical systems are verified and generated by legitimate sources. Thus, VelogCPS avoids a kind of security incidents that impact the authenticity and integrity of the logic and data managed in blockchain networks. By authenticity we refer to provenance authenticity of the involved smart contracts, i.e., the perfect matching between the advertised source-code and the version deployed to the network. Our framework provides a safe blockchain network as it ensures that the entities that participate to a CPS use solely authentic logic. We do this by leveraging block verifier services and enforcing them through the operation workflow. As a result, the middleware guarantees that the participating entities use and share authentic logic. The proposed framework is validated through its implementation on a real blockchain network, employing actual smart contract verifier logic, and through the exhaustive analysis of the temporal behaviour and overhead of the major operations; the obtained results ensure its utility for time-sensitive sytems like CPS and IoT.