The recent worldwide introduction of RemoteID (RID) regulations forces all Unmanned Aircrafts (UAs), a.k.a. drones, to broadcast in plaintext on the wireless channel their identity and real-time location, for accounting and monitoring purposes. Although improving drones' monitoring and situational awareness, the RID rule also generates significant privacy concerns for UAs' operators, threatened by the ease of tracking of UAs and related confidentiality and privacy concerns connected with the broadcasting of plaintext identity information. In this paper, we propose $A^2RID$, a protocol suite for anonymous direct authentication and remote identification of heterogeneous commercial UAs. $A^2RID$ integrates and adapts protocols for anonymous message signing to work in the UA domain, coping with the constraints of commercial drones and the tight real-time requirements imposed by the RID regulation. Overall, the protocols in the $A^2RID$ suite allow a UA manufacturer to pick the configuration that best suits the capabilities and constraints of the drone, i.e., either a processing-intensive but memory-lightweight solution (namely, $CS-A^2RID$) or a computationally-friendly but memory-hungry approach (namely, $DS-A^2RID$). Besides formally defining the protocols and formally proving their security in our setting, we also implement and test them on real heterogeneous hardware platforms, i.e., the Holybro X-500 and the ESPcopter, releasing open-source the produced code. For all the protocols, we demonstrated experimentally the capability of generating anonymous RemoteID messages well below the time bound of $1$ second required by RID, while at the same time having quite a limited impact on the energy budget of the drone.

翻译：近期全球范围内实施的远程识别（RID）法规要求所有无人航空器（UA，即无人机）以明文形式在无线信道中广播其身份和实时位置，以用于核算与监控目的。尽管该规则提升了无人机监控与态势感知能力，但RID法规也引发了UA操作者严重的隐私担忧——明文身份信息的广播使得UA易于被追踪，并带来了相关的机密性与隐私问题。本文提出$A^2RID$协议套件，用于异构商用无人机的匿名直接认证与远程识别。$A^2RID$集成并适配了适用于UA领域的匿名消息签名协议，以应对商用无人机的硬件限制以及RID法规所要求的严格实时性约束。整体而言，$A^2RID$套件中的协议允许无人机制造商根据其性能与约束条件选择最适配的配置方案：即处理密集型但内存轻量的解决方案（称为CS-$A^2RID$），或计算友好但内存消耗较大的方法（称为DS-$A^2RID$）。除正式定义各协议并在我们的设定中严格证明其安全性外，我们还在真实异构硬件平台（即Holybro X-500与ESPcopter）上实现了这些协议并进行了测试，同时开源了生成的代码。实验结果表明，所有协议均能在远低于RID所要求的1秒时限内生成匿名远程识别消息，同时对无人机的能量预算影响十分有限。