A Searchable and Revocable Attribute-based Construction Against Key Regeneration

The Internet of Things (IoT) technology based on cloud-fog computing provides users with various data services by migrating data storage and management to third-party cloud servers and numerous edge fog servers. The attribute-based encryption (ABE) with specific functions can perfectly realize strict access control in the process of private data sharing based on cloud storage. However, existing solutions still do not consider some challenging security issues, such as the key randomization of ABE may lead to the regeneration and abuse of decryption keys related to the subset of authorized attribute sets. This paper proposes an efficient, searchable, and server-assisted revocable attribute-based construction against key regeneration, SRACK, which can significantly reduce the data sharing communication cost by providing users with multi-keyword subset search. The anti-key regeneration component is embedded in the decryption key to solve the key abuse caused by randomization. In addition, the server-assisted user indirect revocation with publicly updateable ciphertext is implemented to meet the practical application of dynamic user groups. The computational offloading of the heavy tasks greatly alleviates the computational load and high latency. We formally prove the security of SRACK within the standard model. The performance analysis confirms the practicality, high efficiency and feasibility of SRACK.