A Prototype Evaluation of a Tamper-resistant High Performance Blockchain-based Transaction Log for a Distributed Database

As data is having an increasingly relevant role in different business fields, ensuring integrity has become fundamental. Modern databases rely on transaction history written on redo logs to allow for data restore. However, if redo logs are (maliciously) forged, data can actually be lost or altered. Due its strong data integrity guarantees, blockchain technology can be employed to ensure log integrity, but its current performance limitations hinder actual exploitations. In previous work, we proposed a layered blockchain-based architecture for distributed (federated) database redo logs: a fast first layer blockchain, anchored to a secure second layer blockchain, based on proof-of-work to achieve strong integrity. Here, we present an implementation and an experimental evaluation of a prototype of that architecture, which employs a total consensus algorithm on the first layer blockchain. Finally, to improve availability and scalability, we refine our solution by investigating, respectively, a Byzantine Fault Tolerant consensus and a Distributed Hash Table solution to shard the first layer blockchain ledger among available nodes.