With the growing needs of data across the world, it almost hard to live without data a day. The fog computing concept is aiming to change the scenarios created by Cloud Computing environments and also to make the data-centric clouds decentralized and localized. Fog devices which aims to be at a shorter distance with the user, access data from the cloud itself. Hence, exchanging of data between the cloud and fog device(s) is required and in this context security and privacy comes into the picture to provide data confidentiality. This paper first shows an architecture for data flow model between the cloud and fog computing and then designs an authentication protocol with proper key establishment between the cloud, fog, and user. We have simulated the proposed protocol using a popular simulator i.e., Scyther and proved that the parameters used in our protocol are strongly protected during protocol execution. Besides, our informal security analysis also confirms robustness of the protocol. Our protocol achieves quick responses in comparison with state-of-the-art because of less computation overhead.

随着全球对数据的需求不断增长，每天几乎没有数据几乎很难生存。雾计算的概念旨在改变由云计算环境创建的方案，并使以数据为中心的云分散和本地化。旨在与用户距离更近的雾设备从云本身访问数据。因此，需要在云设备和雾设备之间交换数据，并且在这种情况下，安全性和隐私性成为图片中的数据提供机密性。本文首先展示了云计算和雾计算之间的数据流模型的体系结构，然后设计了一种在云，雾和用户之间建立适当密钥的身份验证协议。我们已经使用流行的模拟器对建议的协议进行了仿真，即 Scyther证明了在协议执行过程中我们的协议中使用的参数受到了严格的保护。此外，我们的非正式安全性分析也证实了该协议的稳健性。与现有技术相比，我们的协议可实现快速响应，因为其计算开销较小。