The Automatic Dependent Surveillance-Broadcast (ADS-B) is a surveillance technology that becomes mandatory in many airspaces. It improves safety, increases efficiency and reduces air traffic congestion by broadcasting aircraft navigation data. Yet, ADS-B is vulnerable to spoofing attacks as it lacks mechanisms to ensure the integrity and authenticity of the data being supplied. None of the existing cryptographic solutions fully meet the backward compatibility and bandwidth preservation requirements of the standard. Hence, we propose Extended Security in the Air using TESLA (ESAT), an enhanced approach that integrates TESLA, phase-overlay modulation techniques and certificate-based PKI. As a result, entity authentication, data origin authentication, and data integrity are the security services that ESAT offers. To assess compliance with the standard, we designed an SDR-based implementation of ESAT and performed backwards compatibility tests on commercial and general aviation (GA) ADS-B in receivers. Besides, we calculated the 1090ES band's activity factor and analyzed the channel occupancy rate according to ITU-R SM.2256-1 recommendation. Also, we performed a bit error rate analysis of ESAT messages. The results suggest that ESAT is backward compatible, does not incur significant communication overhead, and has an error rate that is acceptable for Eb/No values above 14 dB.

翻译：自动相关监视广播（ADS-B）是一种已在诸多空域强制实施的监视技术。通过广播飞机导航数据，该技术提升了安全性、运行效率并缓解了空中交通拥堵。然而，由于缺乏保障数据完整性和真实性的机制，ADS-B易受欺骗攻击。现有密码学方案均未能完全满足标准对向后兼容性和带宽保持的要求。为此，我们提出基于TESLA的空中扩展安全方案（ESAT），该增强型方法融合了TESLA协议、相位叠加调制技术与证书公钥基础设施（PKI）。由此，ESAT提供了实体认证、数据源认证及数据完整性等安全服务。为评估方案对标准的符合性，我们设计了基于软件无线电（SDR）的ESAT实现，并在商用及通用航空（GA）ADS-B接收机上执行了向后兼容性测试。同时，依据ITU-R SM.2256-1建议书计算了1090ES频段的活动因子，并分析了信道占用率。此外，还对ESAT消息进行了误码率分析。结果表明，ESAT具备向后兼容性，不会产生显著通信开销，且当Eb/No值高于14dB时具有可接受的误码率。