Abstract: VANET is collected of vehicles and roadside infrastructure units (RSUs). Vehicles are equipped with wireless communication devices, which are called On-Board Units (OBUs). The wireless communication devices enable vehicles to exchange traffic related information with each other and with RSUs. VANETs raise many security and privacy concerns at the same time. Malicious users can take advantage of VANET and disturb the whole system. In the previous researchers introduced many techniques and methods, Road information collected to provide navigation service to drivers. Based on the destination and the current location of the driver the system can automatically search for a route that yields minimum traveling delay in a distributed manner using the online information of the road condition. In this survey discuss various VANET security techniques and algorithms to detect and prevent the malicious users in the roadways.