Introduction to Software Defined Radio – For Offensive and Defensive Operations

Grey Fox presents a hands-on introduction to software defined radio for newcomers and security professionals. Drawing on a background in intelligence and special operations cyber work, the speaker focuses on inexpensive commercial hardware, including an RTL-SDR receiver, a HackRF transmitter and a Flipper Zero, paired with free software running on Windows.

The talk starts with passive collection: tuning in to broadcast FM and narrowband transmissions, then decoding aircraft ADS-B signals and plotting them on a map. It moves to sub-gigahertz devices, where a cheap wireless door alarm is captured with a Flipper Zero and replayed. The speaker then uses a HackRF to transmit enough power to stop a key fob and a car unlock signal from reaching their receivers. A Wi-Fi section shows a deauthentication attack that captures a WPA2 four-way handshake, which is then cracked offline against a weak passphrase.

The closing discussion turns to defense. Radio has no firewall equivalent, so the speaker suggests spotting unknown emitters with spectrum tools, looking up FCC IDs for device details, and hardening Wi-Fi with WPA3 and long, unique passphrases. Attendees are also warned that transmitting on protected frequencies can draw attention from regulators and law enforcement.