A secure, efficient and verifiable multimedia data sharing scheme in fog networking system

As an emerging and efficient paradigm for multimedia systems, fog networking has attracted widespread attention over the last few years. However, an increasing number of attacks in the current virtualized environments underlines the importance of secure data sharing. Unfortunately, existing multimedia data sharing schemes are not suitable for the networking systems because of the heavy computational operations, latency-sensitive service, and resource-limited devices. Additionally, authenticated and secure communications are crucial issues related to privacy and trust. In this paper, we propose a secure and efficient data sharing scheme with the computation outsourcing capability in a fog networking system by employing ciphertext-policy attribute-based encryption. The scheme supports dynamic policy updating and delegates attribute revocation processes to the cloud and fog by proxy re-encryption. In particular, we build a secure communication protocol for the revocation parameter transmission. We adopt a chaotic map to generate a one-time key, by which the revocation parameters are encrypted. Then, to ensure legal user accessing to the system, we establish a privacy-preserving communication architecture between the user and cloud, which provides authentication. In addition, our scheme provides a verifiable auditing service for the decryption key and shared file, thus ensuring its correctness. Finally, we analyze the security of the scheme, evaluate its performance, and compare it with related works.