Secure deduplication with reliable and revocable key management in fog computing

A secure deduplication technique removes duplicate data and stores only single copy to efficiently utilize the storage while guaranteeing the privacy of the data. Thus, it is a necessary technology for resource-limited for devices to save storages. However, most of the existing deduplication schemes based on convergent encryption suffer from 1) a convergent encryption key management problem and 2) a dynamic ownership management problem. In key management, convergent encryption generates a number of encryption keys whose size increases linearly with the number of distinct data. In terms of dynamic ownership management, although the ownership of data in a fog device or cloud storage frequently changes in real-world applications, supporting ownership changes are difficult because the convergent encryption keys are only bound to the data. In order to solve these problems, we present a secure deduplication scheme that features reliable and scalable key management based on pairing-based cryptography and supports dynamic ownership management. The proposed scheme avoids additional costs associated with distributing key components on secure channels and ownership keys on the user side yet guarantees secure key and ownership management.