Optimizing Data Distribution to Balance Scalability-Redundancy Trade-off for Collaborative Blockchain Storage

Blockchain protocol ensures security and reliability through immutability and replication of a constantly growing database in a trustless environment. Storage burden of individual nodes keeps increasing with the growing size of data. Collaborative storage schemes for blockchain have shown potential as a way forward to solving the storage challenge. However, most of the existing techniques tend to indiscriminately sacrifice redundancy, which is a basic determinant of blockchain's security and decentralization. Level of redundancy of a collaborative storage system depends on optimization of data distribution. In this paper, we outline a mechanism for the evaluation of a data distribution scheme in terms of its effectiveness for redundancy. We also present a scalable collaborative storage model with optimized data distribution for a balanced trade-off between scalability and redundancy. The proposed model assigns data portions proportional to the storage capacities of nodes. Experiment results show that the storage capacity of the proposed model linearly scales with the number of nodes maintaining an optimum level of redundancy.