Paper 2024/761 Original: eprint.iacr.org/2024/761 ↗

Enabling Secure and Efficient Broadcast Encrypted Search in Cloud Computing

Abstract

The development of cloud computing facilitates data sharing and storage, but it has also raised several security concerns. Public key authenticated encryption with keyword search (PAEKS) enables the encrypted search over cloud data while resisting the insider keyword guessing attacks (IKGAs). However, existing PAEKS schemes are limited to a single receiver, restricting application prospects in the cloud. In addition, quantum computing attacks and key leakage issues further threaten data security. Therefore, designing an encrypted search scheme to resist the above-mentioned attacks is still far-reaching. In this paper, we first propose BroSearch, a secure and efficient broadcast encrypted search scheme in cloud computing. It utilizes lattice sampling algorithms to authenticate the keyword and offers searchability over broadcasting ciphertext while enjoying IKGAs-resistance in a quantum setting. To get around key leakage issues, we then incorporate the minimal cover set technique and lattice basis extension algorithm to construct FS-BroSearch as an enhanced version. Furthermore, we give a rigorous security analysis and a comprehensive performance evaluation of BroSearch and FS-BroSearch. Specifically, BroSearch consumes only 61.11\%, 81.82\%, and 83.33\% of the execution time compared to prior art in terms of ciphertext calculation, trapdoor generation, and search procedures, which is efficient in cloud computing.