This review discusses the theoretical frameworks and application prospects of Zero Trust Security (ZTS) in cloud computing context. This is because, as organisations move more of their applications and data to the cloud, the old borders-based security model that many implemented are inadequate, therefore a model that has a trust no one, verify everything approach is required. This paper analyzes the core principles of ZTS, including micro-segmentation, least privileged access, and continuous monitoring, while critically examining four major controversies: scalability issues, Economics, Integration issues with existing systems, and Compliance to legal requirements. In this paper, having reviewed the existing literature in the field and various implementation cases, the main barriers to implementing zero trust security were outlined, including the dimensions of decreased performance in large-scale production and the need for major upfront investments that can be difficult for small companies to meet effectively. This research shows that there is no clear correlation between security effectiveness and operational efficiency: while organisations experience up to 40% decrease of security incidents after implementation, they note first negative impacts on performance. This study also shows that to support ZTS there is a need to address the context as the economics and operations of ZTS differ in strengths depending on the size of the organizations and the infrastructures. Some of these are: performance enhancement and optimizations, economic optimization, architectural blend, and privacy-preserving technologies. This review enriches the existing literature on cloud security by presenting both the theoretical framework of ZTS and the observed issues, and provides suggestions useful for future research and practice in the construction of the cloud security architecture.

翻译：本综述探讨了零信任安全在云计算背景下的理论框架与应用前景。随着组织将更多应用程序和数据迁移至云端，传统基于边界的安防模型已显不足，因此需要采用"永不信任、持续验证"的新型安全范式。本文系统分析了零信任安全的核心原则，包括微隔离、最小权限访问和持续监控，并批判性审视了四大争议焦点：可扩展性问题、经济成本考量、现有系统集成难题以及法规遵从要求。通过梳理该领域现有文献与实施案例，本文指出实施零信任安全的主要障碍包括大规模生产环境中的性能损耗问题，以及需要大量前期投资——这对中小企业构成显著挑战。研究表明安全效能与运行效率之间不存在明确相关性：虽然组织实施后安全事件发生率最高可降低40%，但普遍观察到初期性能负向影响。本研究发现零信任安全的经济效益与运营效果存在组织规模与基础设施的异质性特征，进而提出四大发展方向：性能增强与优化技术、经济性优化方案、架构融合策略以及隐私保护技术。本综述通过整合零信任安全的理论框架与实践观察，丰富了现有云安全研究体系，为未来云安全架构建设的理论研究与实践部署提供了建设性参考。