In the process

the paper proposes a kind of local credibility model to calculate the credibility of P2P networks.According to the network transactions between nodes

calculation system of time and space overhead

based on the principle of minimum cost system from the network node selecting numbers of local center node

to replace the traditional centralized model of the single center

complete system the credibility of node calculation

and this prevents the traditional central model center node calculation long time consuming.Experiments show that the method can reduce the credibility of the calculation

time-consuming

and improve the calculation of real-time

timely and effectively protect the network security.