In recent years, vehicular ad-hoc network (VANET) is getting a growing interest due to its significant function in terms of vehicle information services and vehicular entertainment applications. In particular, VANET enables parking vehicles (PVs) and roadside units (RSUs) to share their contents with mobile vehicles (MVs), which improves the efficiency of content delivery. However, content delivery in VANET still confronts with several challenges. Due to the selfishness of the PVs, an incentive mechanism is needed to motivate them to contribute their cached contents. Moreover, MVs may be threatened by the trustless or even malicious PVs. In this paper, we propose a reputation-based cooperative content delivery mechanism to improve the efficiency and security of content delivery. We formulate the relationships among MVs, RSUs, and PVs as the two-layer auction game. With the auction game, MVs find the optimal PV and RSU for delivering contents and offering the optimized rewards. In addition, we present a dynamic reputation evaluation model. Based on the feature of content delivery, this model incentivizes these honest PVs and isolates malicious PVs, which improves the security of content delivery. Finally, simulation results show that the proposed mechanism can not only improve the effectiveness of content delivery in VANET, but also avoid the attacks of malicious PVs.

近年来，由于车辆自组织网络（VANET）在车辆信息服务和车辆娱乐应用方面的重要功能，因此受到越来越多的关注。尤其是，VANET使停车车辆（PV）和路边单元（RSU）与移动车辆（MV）共享其内容，从而提高了内容交付的效率。但是，VANET中的内容交付仍面临一些挑战。由于PV的自私性，需要一种激励机制来激励它们贡献其缓存的内容。而且，MV可能会受到不信任甚至恶意PV的威胁。在本文中，我们提出了一种基于信誉的协作内容交付机制，以提高内容交付的效率和安全性。我们制定了MV，RSU，和PV作为两层拍卖游戏。通过拍卖游戏，MV可以找到最佳的PV和RSU，以交付内容并提供最佳的回报。此外，我们提出了动态声誉评估模型。基于内容交付的特征，此模型可以激励这些诚实的PV，并隔离恶意PV，从而提高了内容交付的安全性。最后，仿真结果表明，该机制不仅可以提高VANET中内容传递的有效性，而且可以避免恶意PV的攻击。从而提高了内容交付的安全性。最后，仿真结果表明，该机制不仅可以提高VANET中内容传递的有效性，而且可以避免恶意PV的攻击。从而提高了内容交付的安全性。最后，仿真结果表明，该机制不仅可以提高VANET中内容传递的有效性，而且可以避免恶意PV的攻击。