The Cards-Shuffling scheme solves the Sybil attack in distributed hash table (DHT) theoretically.To overcome cheats of the enemy

a distributed authentication system which constructed by trusted nodes is proposed.The joining nodes are authenticated by the trusted nodes to ensure that the sign and identifiers of the nodes can not be fabricated.Tickets recording the joining process of Cards-Shuffling scheme are also introduced to verify the nodes so that the accumulation of expired identifiers is impossible.The performance of the algorithm proposed by the paper is determined by the number of tickets to be stored.Both the analysis and simulation confirm that there won’t be a great number of tickets to be stored

which guarantees the feasibility of the algorithm.