In IoT, smart sensors enable data collection, real-time monitoring, decision-making, and automation, but their proliferation exposes them to cybersecurity threats. Zero Trust Architecture enhances IoT security by challenging conventional trust models and emphasizing continuous trust verification in the overall \$875.0 billion IoT market projected by 2025. This paper presents a new zero-trust real-time lightweight access control protocol for Cloud-centric dynamic IoT sensor networks. This protocol empowers data owners, referred to as sensor coordinators, to define intricate access policies, blending recipient identifiers and data-related attributes for data encryption. Additionally, the protocol incorporates efficient cryptographic primitives, eliminating the need for reliance on a trusted party. Furthermore, it ensures real-time data access while preserving data confidentiality and user privacy through seamless data upload to the cloud and the offloading of computationally intensive tasks from resource-constrained data owners and sensors. The protocol utilizes Merkle Trees for lightweight, ongoing trust measurement of sensors, ensuring efficient trust assessment by sensor coordinators. Simultaneously, the cloud conducts thorough trust evaluations for network entities including users. Comprehensive security analysis and performance evaluation highlight the protocol's effectiveness in tackling the multifaceted security challenges of IoT ecosystems while ensuring scalability and high availability.

翻译：在物联网中，智能传感器支持数据采集、实时监控、决策制定及自动化，但其广泛应用使其暴露于网络安全威胁之下。零信任架构通过挑战传统信任模型，强调对预计到2025年将达到8750亿美元的全球物联网市场中的持续信任验证，从而增强物联网安全性。本文提出了一种面向云端动态物联网传感器网络的新型零信任实时轻量级访问控制协议。该协议赋予数据所有者（即传感器协调者）定义复杂访问策略的能力，通过结合接收者标识符和数据相关属性实现数据加密。此外，该协议集成了高效密码学原语，无需依赖可信第三方。同时，通过将数据无缝上传至云端并将计算密集型任务从资源受限的数据所有者和传感器卸载，协议在保障数据机密性和用户隐私的前提下实现实时数据访问。该协议利用梅克尔树对传感器进行轻量级持续信任度量，确保传感器协调者能够高效进行信任评估，而云端则对包括用户在内的网络实体执行全面信任评估。全面的安全分析与性能评估表明，该协议在确保可扩展性和高可用性的同时，有效应对了物联网生态系统的多维度安全挑战。