The industrial Internet of Things is flourishing, which is unprecedentedly driven by the rapid development of wireless sensor networks (WSNs) with the assistance of cloud computing. The new wave of technology will give rise to new risks to cyber security, particularly the data confidentiality in cloud-assisted WSNs (CWSNs). Searchable public-key encryption (SPE) is a promising method to address this problem. In theory, it allows sensors to upload public-key ciphertexts to the cloud, and the owner of these sensors can securely delegate a keyword search to the cloud and retrieve the intended data while maintaining data confidentiality. However, all existing and semantically secure SPE schemes have expensive costs in terms of generating ciphertexts and searching keywords. Hence, this paper proposes a lightweight SPE (LSPE) scheme with semantic security for CWSNs. LSPE reduces a large number of the computation-intensive operations that are adopted in previous works; thus, LSPE has search performance close to that of some practical searchable symmetric encryption schemes. In addition, LSPE saves considerable time and energy costs of sensors for generating ciphertexts. Finally, we experimentally test LSPE and compare the results with some previous works to quantitatively demonstrate the above advantages.

中文翻译：

---

云辅助无线传感器网络的轻量级可搜索公钥加密

工业物联网正在蓬勃发展，这是由无线传感器网络（WSN）在云计算的帮助下快速发展所驱动的，这是空前的。新技术浪潮将给网络安全带来新的风险，尤其是云辅助WSN（CWSN）中的数据机密性。可搜索的公共密钥加密（SPE）是解决此问题的一种有前途的方法。从理论上讲，它允许传感器将公钥密文上传到云，并且这些传感器的所有者可以将关键字搜索安全地委派给云并检索预期的数据，同时保持数据的机密性。然而，就生成密文和搜索关键字而言，所有现有的且语义上安全的SPE方案都具有昂贵的成本。因此，本文为CWSN提出了一种具有语义安全性的轻量级SPE（LSPE）方案。LSPE减少了以前工作中采用的大量计算密集型运算。因此，LSPE的搜索性能接近某些实用的可搜索对称加密方案。另外，LSPE节省了用于生成密文的传感器的大量时间和能源成本。最后，我们通过实验测试LSPE，并将结果与​​以前的工作进行比较，以定量证明上述优势。