Client-Based Secure IoT Data Sharing using Untrusted Clouds

Abstract

IoT systems commonly rely on cloud services. However, utilizing cloud providers can be problematic in terms of data security. Data stored in the cloud need to be secured from unauthorized malicious nodes and from the cloud providers themselves. Using a simple symmetric cipher can encrypt the data before uploading and decrypt it while retrieving. However, such a solution can be only applied between two parties with no support for multiple nodes. Whereas in IoT scenarios, many smart devices communicate and share data with each other. This paper proposes a solution that tackles the issue of sharing data securely between IoT devices by implementing a system that allows secure sharing of encrypted data in untrusted clouds. The implementation of the system performs the computation on connectionless clients with no involvement of the cloud server nor any third party. The cloud server is only used as a passive storage server. Analysis of the implemented prototype demonstrates that the system can be used in real-life applications with relatively small overhead. Based on the used hardware, key generation takes about 60 nanoseconds and the storage overhead is only a few kilobytes for large number of files and/or users.