Single-Server Public-Key Authenticated Encryption With Keyword Search and Its Application in IIoT

Cloud-assisted Industrial Internet of Things (IIoT) gathers and analyzes multiple types of data (such as ambient and mechanical data) from physical devices to improve intelligent manufacturing. However, the heavy requirements for data storage and sharing have led to increased demands for efficiency and security in the IIoT system. Public-key Encryption with Keyword Search (PEKS) is an encryption method that provides both data confidentiality and efficient retrieval. Unfortunately, inside keyword guessing attacks (IKGA) have been a persistent issue in PEKS. To resist this attack, Public-key Authenticated Encryption with Keyword Search (PAEKS) has been developed. However, the existing PAEKS schemes are generally proven under intractability assumptions, such as Decisional Bilinear Diffie-Hellman (DBDH) and modified Decision Linear (mDLIN) assumptions, or they involve costly bilinear pairing operations, or rely on two non-colluded cloud servers, which are not suitable for large-scale IIoT applications. In this article, we propose a secure and efficient PAEKS scheme with only one server for cloud-assisted IIoT. Our proposal achieves the IKGA-secure property (i.e., it satisfies the trapdoor privacy and multi-ciphertext indistinguishability) and sidesteps the bilinear pairing operation. Our performance analysis demonstrates the feasibility of our scheme in IIoT by significantly improving computation efficiency (at least 21.97 times) with similar communication overhead.