Capture the Signal (CTS) is a new challenge-based CTF that focuses exclusively on the reverse engineering of radio signals. This activity is also known as “blind signal analysis” as the signals' specification are unknown to the attacker.

In normal circumstances, the game is hosted on site at conferences world-wide, where our radio signals are distributed “over IP”. The use of IP eliminates the complexity of deploying actual radios and transmitting RF over the air.

Each radio signal corresponds to a challenge. The challenges are sorted by difficulty, and each solved challenge gives you access to the next one. In other words, the flag contained in each signal represents the clue to the next radio signal. The more points are scored, the closer the contestant is to win.

Participants are also welcome to use Software Defined Radio (SDR) equipment to interact directly with RF signals over the air.

This contest is organized by renowned community radio-hackers for researchers, hackers, and practitioners in the field!


Follow our Twitter account for more recent news :-)

23.11.2021: We get back to in-person events with our participation at HITB Cyberweek in Abu Dhabi! :-)

16.09.2021: Our presentation at Black Hat USA Arsenal 2021 is online! Download here

16.09.2021: We are happy helping running the Capture the Flag event at GRCon 2021: The GNU Radio Conference