Enhancing Mobile Crowdsensing Security: A Proof of Stake-Based Publisher Selection Algorithm to Combat Sybil Attacks in Blockchain-Assisted MCS Systems

In a blockchain-assisted Mobile CrowdSensing (MCS) System, individuals can generate as many blockchain identities as they desire, facilitating the execution of a Sybil attack. A Sybil attack can significantly impact such a system due to incorporating a reward mechanism and a majority-based data validation mechanism. An attacker can launch a Sybil attack with selfish or malicious intentions to maximize benefits from the system or to narrow down the reputation of the data requester (subscriber) and the system. Consequently, a Sybil attacker can discourage honest data collectors (publishers) and subscribers from participating, impeding the system’s potential success. In this paper, we propose a Sybil attack prevention cum avoidance mechanism to narrow down the effect of it in the blockchain-based MCS systems while maintaining the system’s requirements. The proposed mechanism incorporates a novel randomized publisher selection algorithm, leveraging the Proof-of-Stake (PoS) concept to render executing a Sybil attack costly and impractical. The simulation results show the effectiveness of the proposed mechanism.