Blockchain-Assisted Keyword Search Scheme for SWIM Service Based on Improved CSC-Cuckoo Filter

Abstract

With the rapid development of the civil aviation industry, the demand for secure sharing of civil aviation data is increasing. As a global platform for secure sharing of civil aviation data, the security of the System Wide Information Management (SWIM) system is of great concern. SWIM adopts a service-oriented architecture and realizes the interaction of civil aviation data through a publish-subscribe model. To protect the service privacy while enabling subscribers to subscribe to the service quickly and securely, this paper proposes an efficient Circular Shift and Coalesce-Cuckoo Filter (CSC-CF)-based service Keyword Search (CCKS) scheme assisted by blockchain. This scheme uses the Symmetric-key Hidden Vector Encryption (SHVE) algorithm to encrypt and match service indexes and trapdoors to protect service privacy; the CSC-CF structure is applied to keyword search, which can effectively improve the efficiency of SWIM user subscription service. To improve search accuracy and space utilization, we propose the improved CCKS (ICCKS) scheme by optimizing the query algorithm of CSC-CF and setting a threshold for the number of keyword query failures. ICCKS improves search accuracy by 5–20% compared to CCKS when the filter’s space utilization is between 60 and 90%. Additionally, the scheme stores service topic indexes and registry on the blockchain and implements a smart contract to match indexes and subscription trapdoors, ensuring the integrity and trustworthiness of service topics and registry. Security analysis and experimental simulations demonstrate that the scheme is effective and secure in the SWIM system.