Testimonium: A Cost-Efficient Blockchain Relay
This addresses the issue of high costs and centralization in cross-chain data verification for blockchain developers and users, representing a strong specific gain rather than an incremental improvement.
The paper tackles the problem of costly and centralized blockchain interoperability by introducing Testimonium, a blockchain relay scheme that achieves up to 92% cost reduction over existing solutions while remaining fully decentralized.
Current blockchain technologies provide very limited means of interoperability. In particular, solutions enabling blockchains to verify the existence of data on other blockchains are either very costly or are not fully decentralized. To overcome these limitations, we introduce Testimonium, a novel blockchain relay scheme that applies a validation-on-demand pattern and the on-chain execution of Simplified Payment Verifications to enable the verification of data across blockchains while remaining fully decentralized. Evaluating the scheme for Ethereum-based blockchains shows that Testimonium achieves a cost reduction of up to 92% over existing solutions. As such, the scheme lays a strong foundation for generic blockchain interoperability. For instance, it enables the development of an atomic-commit protocol for distributed transactions across blockchains.