The Vehicular Ad Hoc Network (VANET) enhances the traffic efficiency and improves the traffic environment,however,it brings up security threats such as information tampering,forgery,as well as privacy disclosure.Thus,the message authentication scheme consistent with characteristics of the VANET is in urgent need.In this paper,we take the option of privacy protection scheme for VANET based on vehicle classification in urban transport system,which includes classification and assignment of trust values for different types of vehicles.For private vehicles,a pseudonym multiple signature scheme is employed to sign the message;while for the public vehicles and RSUs without identity privacy protection requirement,we can use the RSA signature scheme to sign messages.At the same time,the signature is required to accumulate the trust value of the strategy to improve the message reliability.Finally,SUMO,MOVE and NS2 are employed to jointly simulate the proposed scheme,and the result shows that the scheme is more flexible and less time-consuming compared with other schemes proposed in references of[19-20].