Blockchain-Based Metadata Protection for Archival Systems

Long-term archival storage systems must protect data from powerful attackers that might try to corrupt or censor (part of) the documents. They must also protect the corresponding metadata information, which is essential to maintain and rebuild the stored data. In this practical experience report, we present metablock, a metadata protection system leveraging the Ethereum distributed ledger. We combine metablock with an existing secure long-term data archival system to provide a scalable design that allows external auditing, data validation and efficient data repair. We reflect on our experiences in using a blockchain for metadata protection, with the goal of providing valuable insights and lessons for developers of such secure systems, by highlighting the potential and limitations of the approach. Our prototype is available at https://github.com/ArnaudLhutereau/mb.