PoPF: A Consensus Algorithm for JCLedger

JointCloud is a new generation of cloud computing model which facilitates developers to customize cloud services. JCLedger is a blockchain based distributed ledger for JointCloud computing which can make cloud resources exchange more reliable and convenient, and it is the combination of JointCloud and BlockChain. One of the most important elements for creating JCLedger is the consensus algorithm. PoW (Proof of Work) is the consensus algorithm for Bitcoin, which is proved to be quite safe but needs much computing power. The original PoW is not suitable for JCLedger because the identities of participants are not equal in computing power, which may lead to accounting monopoly, and the throughput cannot satisfy the requirement of the massive and high-frequency transactions in JointCloud. In this paper, we propose a PoW based consensus algorithm called Proof of Participation and Fees (PoPF), which can save much computing power and handled transactions more efficiently for JCLedger. In our design, only the candidates have the opportunities for mining and the candidates are chosen according to the ranking which is determined by two factors: the times of the participant to be the accountant and the fees the participant has paid. The difficulty for candidates of solving the PoW hash puzzle is different (the higher ranking means easier for mining). The simulation experiment shows that the distribution of accountants is well-balanced, that is to say, the unequal computing power of participants in JointCloud is shielded, and all the users who have enough contribution in JCLedger will have the opportunities to be accountants.