Nebula: A Blockchain Based Decentralized Sharing Computing Platform

Nowadays, there is a considerable amount of idle computers whose computing resources are partially wasted. On the other hand, the demand of resources is rapidly growing, since the explosion of data and the complexity of algorithms. To settle the contradictions, we develop Nebula, a decentralized platform based on blockchain for sharing computing resources. Nebula leverages blockchain to gather the scattered computing resources and provide a secure and vibrant computation trading market. Compared to traditional cloud platform, Nebula guarantees extra security because all transactions in this platform are validated by smart contracts. No one can tamper the transaction orders which are recorded by a widely distributed ledger. In Nebula, the resource consumer can order resources from resource providers with a very simple declarative script. When a deal is done, consumers can submit jobs to suppliers with a docker instance. Moreover, we model the order matching procedure of users' requests into a global maximum matching problem in a bipartite graph. We adopt the Hungarian algorithm to find an order matching policy, bringing an 10% increase to the matching rate in our best case. Moreover, we leverage the Proof of Authority (PoA) consensus algorithm called Clique, rather than Proof of Work (PoW) to increase the efficiency of Nebula, which provides nearly no less security but requires negligible computation on reaching consensus. To our best knowledge, we are the first to propose a general blockchain based platform for sharing computing resources, which fully utilizes the features of blockchain to achieve the scalability, the optimal order matching and a high performance.