TODAY, EXPLOITATION OF A VEHICULAR AD HOC NETWORK CAN SIGNIFICANTLY IMPROVE TRAFFIC SAFETY AND ROAD PRODUCTIVITY, AND REDUCE ENVIRONMENTAL IMPACT. GENERALLY, THE SERVICES PROVIDED ON THE VEHICULAR NETWORK INCLUDE TRAFFIC INFORMATION FOR DRIVERS SUCH AS ACCIDENT INFORMATION, EMERGENCY CONDITIONS, WEATHER FORECASTING AND SHARING MULTIMEDIA INFORMATION, WHICH HELPS DRIVERS TO SAFETY. BUT THE ISSUE OF SECURITY AND PRIVACY IS A MAJOR CHALLENGE IN FAILING TO COMMUNICATE IN A VEHICULAR NETWORK ENVIRONMENT. TO ENSURE THE ACCURACY OF THE INFORMATION, THE MESSAGE SENDER MUST BE AUTHENTICATED TO PREVENT DENIAL OF THE VEHICULAR NETWORK. BUT THE PROBLEM IS DRIVERS FOR THEIR PRIVACY DO NOT HAVE THE DESIRE TO AUTHENTICATE FOR TRACKING AND THE NEXT PROBLEMS. THEREFORE, ANONYMOUS AUTHENTICATION IS ONE OF THE MAIN CHALLENGES OF THE VEHICULAR NETWORK. IN THIS ARTICLE, WE REVIEW THE STRATEGIES PROPOSED FOR PRIVACY AND WE PUT THEM IN THREE CATEGORIES: PSEUDONYMS, GROUP SIGNATURE, COMBINED METHOD.