Frauenthaler, PhilipPhilipFrauenthalerSigwart, MartenMartenSigwartSpanring, ChristofChristofSpanringSober, Michael PeterMichael PeterSoberSchulte, StefanStefanSchulte2022-03-072022-03-072020-11IEEE International Conference on Blockchain (Blockchain 2020)http://hdl.handle.net/11420/11817Current blockchain relay schemes require the immediate validation of each relayed block header by the destination blockchain. This leads to high operating cost when deploying these relays between Ethereum-based blockchains where validating block headers on-chain is computationally expensive.To overcome these limitations, we introduce a novel relay scheme that employs a validation-on-demand pattern combined with economic incentives to reduce the cost of operating a relay between Ethereum-based blockchains by up to 92%. With this relay scheme, decentralized interoperability between blockchains like Ethereum and Ethereum Classic becomes feasible.enblockchain interoperabilityblockchain relaycross-blockchain communicationsimplified payment verificationConference Paper10.1109/Blockchain50366.2020.00032Conference Paper