Defense against sybil attack in blockchain based on improved consensus algorithm

Sybil attack is one of the most serious security threats in distributed systems. This paper proposes an anti-sybil consensus algorithm, which can effectively defend against sybil attacks. This algorithm is an improved version of the PBFT algorithm. It introduces a reputation system, which assigns trust scores to nodes based on their behavior, and uses these trust scores to determine their voting weight in the consensus process. In order to evaluate the performance of the algorithm, the simulation is performed on a blockchain network with different number of nodes and sybil attackers. The results show that the algorithm can effectively defend against sybil attacks. Compared with the existing methods, the anti-sybil consensus algorithm in this paper has several advantages. First, it is lightweight and easy to implement, which makes it suitable for resource-constrained devices. Second, the performance of the improved algorithm has not significantly decreased. In short, the anti-sybil consensus algorithm proposed in this paper provides a practical solution for protecting distributed systems from sybil attacks.