Cholula: Fast, Fault-tolerant, and Strongly Consistent Off-chain Object Storage

Emerging security technologies such as Blockchain are prominent to secure data. Blockchain inherits the advanced principles of cryptography and decentralization. This paper explores an appropriate design for distributed object storage systems for off-chain data. Our system Cholula has the following salient features: (i) Strong consistency; (ii) Optimal fast-path latency (1 RTT when there is no conflicting write); (iii) Tolerance of Byzantine servers; (iv) Security (preventing from an imposter attack); and (v) Censorship-resistance. We present our design and evaluation in this work. We demonstrate that Cholula has a better performance than the state-of-the-art object storage system Giza (the system behind Microsoft OneDrive) and Cassandra in the context of geo-replicated off-chain data.