Backscatter communication (BC) offers a promising power-efficient communication paradigm for wireless devices with constrained energy resources. However, the innate openness and broadcast characteristics of BC raise considerable security concerns. To address this, physical layer authentication has emerged as a primary solution to enable secure BC. To facilitate efficient authentication on multiple backscatter devices (BDs), batch authentication becomes essential. Nevertheless, existing schemes have not yet bridged the research gap regarding effective batch authentication on mobile BDs with high scalability support. This paper proposes BatchAuth, a physical layer batch authentication scheme designed to authenticate multiple BDs simultaneously by leveraging orthogonal frequency-division multiple access (OFDMA) technology. BatchAuth utilizes two factors, received signal strength (RSS) and multiple channel impulse responses (CIRs), to authenticate a group of BDs and leverages a channel correlation coefficient to offset performance loss and support BD dynamicity. What’s more, a backscatter waveform design facilitates an access point (AP) in estimating the CIRs from backscattered signals. Additionally, BatchAuth possesses the capability to detect and trace potential attackers by analyzing the specific characteristics of orthogonal subcarriers to facilitate countermeasure. In particular, BatchAuth demonstrates significant potential on scalability in large-scale BC systems and multiple-input multiple-output (MIMO) systems. Theoretical analysis on BatchAuth security and extensive simulations under various settings by comparing with cutting-edge schemes further validate its commendable performance with regard to accuracy, robustness, efficiency, and scalability.

中文翻译：

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BatchAuth：适用于多个反向散射设备的物理层批量身份验证方案


反向散射通信 （BC） 为能源资源受限的无线设备提供了一种有前途的高能效通信模式。然而，BC 与生俱来的开放性和广播特性引发了相当大的安全问题。为了解决这个问题，物理层身份验证已成为实现安全 BC 的主要解决方案。为了促进在多个反向散射设备 （BD） 上进行高效身份验证，批量身份验证变得至关重要。然而，现有的方案尚未弥合在具有高可扩展性支持的移动 BD 上进行有效批量身份验证的研究差距。本文提出了 BatchAuth，这是一种物理层批量认证方案，旨在通过利用正交频分多址 （OFDMA） 技术同时对多个 BD 进行认证。BatchAuth 利用接收信号强度 （RSS） 和多通道脉冲响应 （CIR） 两个因素来验证一组 BD，并利用通道相关系数来抵消性能损失并支持 BD 动态性。此外，反向散射波形设计有助于接入点 （AP） 根据反向散射信号估算 CIR。此外，BatchAuth 还能够通过分析正交子载波的具体特性来检测和追踪潜在的攻击者，以便于对策。特别是，BatchAuth 在大规模 BC 系统和多输入多输出 （MIMO） 系统中的可扩展性方面表现出了巨大的潜力。对 BatchAuth 安全性的理论分析和各种设置下的广泛模拟，通过与尖端方案的比较，进一步验证了其在准确性、稳健性、效率和可扩展性方面的值得称道的性能。