Abstract: At present,in the process of trust evaluation of trust model,because the sources of evaluation data are not uniform,the ability of different nodes to obtain evaluation data is different,and the recognition degree of different nodes to data is also different,the computational results are low accuracy,subjective and difficult to be used as a reference.Aiming at these problems,this paper proposed a blockchain-based peer-to-peer network trust model,named ChainTrust.The evaluation sequence graph is defined.The indirect trust weight is determined according to the reliability of the indirect trust degree of the evaluation node.Meanwhile,this paper improved the current blockchain structure,by using the Merkle Patricia tree and the binary Merkle tree to store the evaluation data,and gave the corresponding storing and reading algorithms.Simulation and analysis results show that ChainTrust can better resist a variety of malicious attacks,thus reducing the impact from the collusion attack,changing the sensitivity of the model by adjusting the model parameters.Therefore,ChainTrust is effective and has high flexibility and universality.

Key words: Blockchain, Collusion attack, Evaluation data, Evaluation sequence graph, Merkle patricia tree, Trust model