A dispute arbitration protocol based on a peer-to-peer service contract management scheme

Cloud computing has provided an attractive model for business service delivery. However, accountability aspects, mainly the monitoring of the execution of a service contract, liability assignment and dispute arbitration are still lacking. On the one hand, the traditional centralized monitoring and the trusted-third party (TTP) based arbitration solutions are not suitable for the distributed cloud environment. On the other hand, a decentralized solution also faces challenges in guaranteeing fairness, accuracy and sustainability. To address this issue, this paper firstly proposes an innovative service contract management scheme that facilitates the monitoring of the execution of a service contract in a peer-to-peer environment, inspired by the concept of blockchain in Bitcoin. Secondly, on top of the scheme it presents a novel dispute resolution protocol based on the Byzantine agreement and the commitment scheme. Thirdly, it identifies the optimal settings of the key parameters of the protocol through a set of experiments and scenario analysis, aiming to strike the balance of fairness, accuracy, incentive maximization for the honest arbiters and cost minimization for the overall arbitration process. With this approach, service participants can be held accountable in a truly distributed environment without the presence of a central authority, which increases businesses confidence on adopting cloud services.