P2CSTORE: P2P and Cloud File Storage for Blockchain Applications
Marcelo Silva, Miguel Matos, Miguel Pupo Correia · 2020
We live in an era where storage systems are of major importance. In this work, we focus on storing files for use in blockchain applications. A blockchain is a distributed, replicated system, that contains a ledger of operations and executes programs known as smart contracts. Although a blockchain may be considered a data storage system, public blockchains like Ethereum charge the users per each byte stored making them expensive to store large files. Therefore, applications based on blockchains often use an external file storage system, usually peer-to-peer (P2P). We propose P2CSTORE, a new storage system for blockchain applications using both P2P and cloud subsystems. This way we aim to provide application developers with the flexibility of choosing the best place for their files, depending on aspects such as the trust they place in peers and clouds. We show the benefits of the approach with a blockchain application that manages education certificates. The application stores hashes of the certificates in the cloud and the certificates themselves in our storage system.