Truncate after preamble: PHY-based starvation attacks on IoT networks

We present and evaluate Truncate-after-Preamble (TaP) attacks, whereby a receiver cannot decode an incoming signal despite good channel conditions. In a TaP attack, the attacker announces a large payload length using a standard preamble and packet length field, but omits to transmit the payload. We implement the TaP attack on a SDR platform, and evaluate the effectiveness of the attack on five Zigbee and seven Wi-Fi devices sold by different manufacturers. We show that all of the Zigbee devices are vulnerable to the attack, while the Wi-Fi devices are vulnerable to the attack to varying degrees. Chiefly, we show that an attacker can cause over 90% packet loss on a Zigbee or Wi-Fi channel, using respectively six or five orders of magnitude less energy than a constant jammer would. Finally, we present several methods, with different degrees of sophistication, for detecting the attacks.