Dynamic negotiation of user behaviour via blockchain technology in federated system

With the increasing number of network systems and users, there are a myriad of data generated by users' daily activities, then comes the big data era. The focus of this paper tries to realise user trust negotiation with the help of blockchain technology. Therefore, in this paper, how to not only detect a malicious user but also negotiate the users' trust value among network systems are discussed. The dominating work is as follows: firstly, a variety of decentralised systems form a federated system. Secondly, every user behaviour profile is anchored on the user behaviour blockchain among the federated system, which concludes the trajectory of a user's overall behaviours, on the basis of user behaviour profile, the trust negotiation model based on practical byzantine fault tolerance (PBFT) is proposed. Finally, a scenario based on the model is proposed and its safety problems are analysed, which makes a new try in dynamic negotiation of user trust.