Poolcoin : Toward A Distributed Trust Model For Miners' Reputation Management In Blockchain

In blockchain, transactions between parties are regrouped into blocks, in order to be added to the blockchain's distributed ledger. Miners are nodes of the network that generate new blocks that meet the consensus protocol. Thus, when a miner adds a valid block to the distributed ledger, the miner is rewarded. Due to the difficulty of the problem to be solved by the miner in order to find a valid block, it becomes difficult to a single miner to gain rewards. Therefore, miners join mining pools, where the powers of miners are federated to ensure stable revenues for miners. In public blockchains, access to mining pools is not restricted, which makes mining pools vulnerable to considerable threats such as: block withholding (BWH) attacks and distributed denial of service (DDoS) attacks. In the present work, we a new blockchain named PoolCoin that manages reputation in mining pools. In addition, we provide a trust model for PoolCoin, inspired by the job market signaling model. The proposed PoolCoin blockchain allows pool managers to accept trusted miners in their mining pools, while miners are able to evaluate pool managers. The performance evaluation is conducted and the obtained simulation results are presented and discussed. In order to study the efficiency of the proposed trust model, a performance evaluation was provided. Thus, the model parameters' are optimized in order to detect and exclude misbehaving miners, while honest miners are maintained in the mining pool.