Secure Data Sequence Query Framework Based on Multiple Fogs

Fog computing is used to process a large amount of data produced by terminal devices where fog nodes are the closest acquirers to the terminal devices. In fog computing, the processed data may be tampered with or illegally captured by some malicious nodes while the data is transferred or stored. So, when some applications need to require data process with high security, fog computing must provide a security approach to secure and check the final results. In this paper, we propose a secure data sequence query framework based on multiple fog servers, where we use multiple fog servers to store and provide data hashing values to verify corresponding data sequence. In the proposed scheme, the cloud server needs to pre-designate some Merkle hashing tree topologies to the fog network, then the fog server directly acquires related data from leaf-nodes (fog nodes) according to one of the pre-designated Merkle hashing tree topologies; at the same time, an actual Merkle hashing tree is constructed according to the selected Merkle hashing tree topology in the fog network. In fog computing, the related fog nodes participate in computing and transferring the hashing values on data, then the corresponding root node uses the
$(t,n)$
threshold secret sharing scheme to compute and distribute the sub-secrets of the root value to other fog servers. Therefore, when a user requests a data sequence from a fog server, the fog server may immediately respond to the request and the other fog servers can provide the sub-secrets of hashing root value to verify the corresponding data sequence. Our proposed framework can ensure that users may obtain required data fast, accurately and reliably. Additionally, based on the data query security requirements of fog computing, we analyze the security of our proposed scheme. Our proposed scheme not only guarantees the reliability of data but also effectively protects data against various attacks.