Vehicular Ad Hoc networks (VANETs) is a new emerging technology that aims at connecting vehicles using wireless communication technologies. With the emergence of VANETs, new advanced applications have emerged away which aim at enhancing driving safety and traffic management. These applications exploit the huge amount of data, shared between vehicles and infrastructure, through advanced data analysis. Due to resources limitation of vehicles, this increasing volume of data is stored on powerful edge computing servers spread over the VANETs infrastructure. However, these edge servers are not fully trusted, which rise new serious security and privacy challenges regarding the shared data between vehicles. In this work, we propose a new data-sharing scheme that protects the privacy of vehicles and drivers. We base our construction on consortium blockchain, smart contracts and Zero-Knowledge Proofs (ZKP) to propose a decentralized and anonymous data-sharing scheme. In addition, we propose a fine-grained data storage scheme on the top of blockchain, based on publish-subscribe model to enhance the data management. We confirm the efficiency of our scheme through extensive simulations and experiments. The numerical results showed that our protocol achieves a reasonable efficiency while guaranteeing a high level of security.