HIBPEKS: Hierarchical Identity-Based Puncturable Encryption With Keyword Search Over Outsourced Encrypted Data

With the rapid advancement of cloud computing and the exponential growth of data, the demand for secure data querying and sharing has become increasingly prominent. Identity-Based Encryption with Keyword Search (IBEKS) and Hierarchical IBEKS (HIBEKS) address the issue of secure data querying, as it enables resource-constrained clients to effectively search for encrypted data stored in the cloud. However, existing HIBEKS schemes lack flexible data-query mechanisms among users in the same level, are highly vulnerable to attacks launched by quantum computers and Keyword Guessing Attacks (KGA), and lead to relatively high end-to-end latency. To meet more complex and diverse application requirements and address these vulnerabilities, we introduce a novel primitive called Hierarchical Identity-Based Puncturable Encryption with Keyword Search (HIBPEKS). The decryption keys held by higher-level users are capable of generating decryption keys for lower-level users, thereby enhancing the ability to perform multi-level encrypted data queries within the user group. In addition, to control the query of encrypted data, higher-level users can use specific tags to puncture decryption keys (for lower-level users), so that lower-level users will no longer be able to query the parts of the data associated with the punctured tags. Technically, we have improved the previous lattice-based IBEKS schemes and implemented an efficient and flexible data query mechanism in a hierarchical setting by exploiting Puncturable Encryption (PE) techniques. Moreover, we formalize the security model of HIBPEKS and prove its security within the framework of the random oracle model. Finally, we experimentally evaluate HIBPEKS and show that HIBPEKS is computationally efficient and practical.