Satellite Based Augmentation System (SBAS) provides the corrections and integrity information to users, but as its signal format is opened to the public and Global Navigation Satellite System (GNSS) spoofing technology becomes more realistic, more feasible and cheaper. It's foreseeable that there will be risks of spoofing threats against SBAS in the future. SBAS signal authentication technology provides a system-level solution to spoofing threats by adding special markers to SBAS signals so that receivers can verify whether the SBAS signals are from the on-orbit Geostationary Earth Orbit (GEO) satellites or whether the signal information has been forged and tampered with. First, this article introduces the existing anti-spoofing methods that can be applied to SBAS, especially the Elliptic Curve Digital Signature Algorithm (ECDSA) and Timed Efficient Stream Loss-Tolerant Authentication (TESLA) protocols. Then it discusses four possible solutions in a combination with the existing SBAS Interface Control Document (ICD). Two main Key Performance Indicators (KPIs), Time Between Authentication (TBA) and Authentication Latency (AL), obtained in the four main scenarios are compared. By analyzing the EGNOS Authentication Security Testbed (EAST) test simulation results of European Geostationary Navigation Overlay Service (EGNOS) in Europe, the impact of SBAS after joining the authentication service is obtained.

中文翻译：

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SBAS认证技术进展

星基增强系统 (SBAS) 向用户提供修正和完整性信息，但随着其信号格式向公众开放，全球导航卫星系统 (GNSS) 欺骗技术变得更现实、更可行和更便宜。可以预见，未来将存在针对SBAS的欺骗威胁风险。SBAS 信号认证技术通过在 SBAS 信号中添加特殊标记，提供系统级的欺骗威胁解决方案，以便接收器验证 SBAS 信号是否来自在轨地球静止轨道 (GEO) 卫星或信号信息是否被伪造并被篡改。首先，本文介绍了现有的可以应用于SBAS的反欺骗方法，特别是椭圆曲线数字签名算法 (ECDSA) 和定时高效流丢失容忍认证 (TESLA) 协议。然后结合现有的 SBAS 接口控制文档 (ICD) 讨论四种可能的解决方案。比较了在四个主要场景中获得的两个主要关键性能指标 (KPI)，即身份验证之间的时间 (TBA) 和身份验证延迟 (AL)。通过分析欧洲地球同步导航覆盖服务（EGNOS）在欧洲的EGNOS Authentication Security Testbed（EAST）测试模拟结果，得到加入认证服务后SBAS的影响。比较了在四个主要场景中获得的两个主要关键性能指标 (KPI)，即身份验证之间的时间 (TBA) 和身份验证延迟 (AL)。通过分析欧洲地球同步导航覆盖服务（EGNOS）在欧洲的EGNOS Authentication Security Testbed（EAST）测试模拟结果，得到加入认证服务后SBAS的影响。比较了在四个主要场景中获得的两个主要关键性能指标 (KPI)，即身份验证之间的时间 (TBA) 和身份验证延迟 (AL)。通过分析欧洲地球同步导航覆盖服务（EGNOS）在欧洲的EGNOS Authentication Security Testbed（EAST）测试模拟结果，得到加入认证服务后SBAS的影响。