The proliferation of IoT and V2X systems generates unprecedented sensitive data at the network edge, demanding privacy-preserving architectures that enable secure sharing without exposing raw information. Contemporary solutions face a fundamental privacy-efficiency-trust trilemma: achieving strong privacy guarantees, computational efficiency for resource-constrained devices, and decentralized trust simultaneously remains intractable with single-paradigm approaches. This survey systematically analyzes 75 technical papers (2007--2025) through a novel three-dimensional taxonomy classifying architectures into Decentralized Computation, Cryptography-based, and Distributed Ledger approaches. Temporal analysis reveals dramatic acceleration during 2024--2025, with 48% of all papers published in this period -- Decentralized Computation dominates at 44% of contributions and 59% of 2025 publications. Comprehensive Security Threat Mapping and Technology Maturity Assessment demonstrate that mature solutions occupy narrow design regions excelling in one or two dimensions while compromising others, conclusively validating the trilemma hypothesis. We identify emerging hybrid architectures combining complementary paradigms as the essential path forward. Critical challenges including security guarantee composition across layers, multi-layer coordination overhead minimization, and post-quantum security integration must be addressed for practical deployment in next-generation intelligent transportation systems and IoT ecosystems.

翻译：物联网与车联网系统的激增在网络边缘产生了前所未有的敏感数据，这要求隐私保护架构能够在无需暴露原始信息的前提下实现安全共享。现有解决方案面临隐私-效率-信任的三难困境：同时实现强隐私保证、资源受限设备的计算效率以及去中心化信任，单一范式方法仍难以兼顾。本综述通过新颖的三维分类法（将架构分为去中心化计算、密码学基础与分布式账本三类），系统分析了75篇技术文献（2007–2025年）。时序分析显示，2024–2025年间研究呈现爆发式增长，该时段发表的论文占总数的48%——其中去中心化计算类贡献占比最高（占总数的44%，占2025年文献的59%）。全面的安全威胁映射与技术成熟度评估表明，成熟解决方案仅占据狭窄的设计区域，它们在一到两个维度表现优异，却往往在其他维度有所妥协，这最终验证了三难困境假说。我们认为，融合互补范式的新兴混合架构是未来发展的关键路径。为实现在下一代智能交通系统与物联网生态系统中的实际部署，必须解决跨层级安全保证的组合、多层协调开销最小化以及后量子安全集成等关键挑战。