Device-to-device communication is a promising technology that can offload heavy traffic in 5G networks. However, due to its open nature, there are several security issues. The LTE-A standard introduces security and protection mechanisms, which include mutual authentication between the UEs and the eNB. Unfortunately, D2D communications still face various threats: jamming, data modification, free-riding, and privacy violation. In this article, we first give an architecture for an LTE-D2D system and its application scenarios with various security threats and requirements. Then we investigate privacy concerns in terms of location privacy, identity privacy, and data privacy. Afterward, we propose security solutions from aspects of application-layer security and physical-layer security, respectively. Further, we propose two frameworks for cross-application-physical-layer security methods. Finally, the challenges and future research directions are presented.

中文翻译：

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5G 中的安全意识和隐私保护 D2D 通信

设备到设备通信是一种很有前途的技术，可以减轻 5G 网络中的繁重流量。但是，由于其开放性，存在几个安全问题。LTE-A 标准引入了安全和保护机制，其中包括 UE 和 eNB 之间的相互认证。不幸的是，D2D 通信仍然面临各种威胁：干扰、数据修改、搭便车和侵犯隐私。在本文中，我们首先给出了一个 LTE-D2D 系统的架构及其具有各种安全威胁和要求的应用场景。然后我们从位置隐私、身份隐私和数据隐私方面调查隐私问题。随后，我们分别从应用层安全和物理层安全方面提出了安全解决方案。进一步，我们提出了两个跨应用程序物理层安全方法的框架。最后，提出了挑战和未来的研究方向。