An Efficient Trust Management using Feedback Credibility Evaluation Method in Fog Computing

Trust of a fog node in fog computing plays a vital role when a user is not familiar with the fog node and can be calculated using the feedback provided by other users. Malicious feedbacks lead to degraded user satisfaction, degraded reputation of good fog nodes, and various attacks such as bad-mouthing attacks, ballot stuffing, Sybil attacks, whitewashing attacks, etc. This work proposes a novel checkers-based feedback credibility evaluation method to identify malicious feedbacks and omits them while evaluating the trust of a fog node. Checkers are the users who have already taken service from the fog node and are honest. The method uses aggregated opinion of checkers and aging factor of checkers to decide the credibility of feedbacks. The proposed method limits the impact of various possible attacks caused by malicious feedbacks. Performance evaluation shows that the method performs well even when malicious feedbacks are present in the system.