The present invention provides a vehicle 
fog data light-weight anonymous access 
authentication method based on 
blockchain assistance, and relates to the technical field of 
network communication safetyof urban traffic operation management. The method comprises the steps of: arranging one witness node (WP) in a management range of each service manager (SM), initializing 
system parameters through antrusted center AD, and registering the SM and a OBU (
On Board Unit); allowing the SM to authenticate the validity of the OBU, storing the 
authentication information, 
broadcasting an 
authentication result to the WP, and providing 
fog service to the OBU according to the authentication result by a roadside facility unit RSU; and writing the authentication result into a 
public account by the WP to complete OBU 
consensus. The vehicle 
fog data light-weight anonymous access authentication method based on 
blockchain assistance can protect the 
user privacy information while ensuring the identity authenticity of a vehicle user accessing the fog service so as to achieve the vehicle 
anonymous authentication and allow users to select the time and the frequency of replacement of the pseudonym by themselves; the non-interactive autonomous cross-domain authentication is achieved, and the communication 
delay is effectively reduced; and moreover, the 
authentication information management is simplified,and the risk that a single 
database is tampered is effectively avoided.