If you weren't already aware, KrakenSDR is our 5-channel coherent radio based on RTL-SDRs, and it can be used for applications like radio direction finding. KrakenSDR is in stock and can be purchased from CrowdSupply or Mouser. More information is also available on our website at krakenrf.com.
Last month we used the KrakenSDR to find the location of a low power FM transmitter. Now in this video we're using KrakenSDR to find the location of GSM base station transmit towers for four frequencies. We're also using the multi-vfo feature to capture the bearing data of these four frequencies simultaneously which can save us some search time.
Once we've found the first transmit tower, we already have some logged bearing data that can be used to help us find the second tower faster. Then the third and fourth towers are even faster to find due to even more data having already been collected.
Interestingly, it also turns out that the first frequency we search for is actually being used by another tower that we pass along the way back. The location of this tower was picked up on the drive back to the first tower. It's possible that these two towers which are a few kilometers apart are covering different areas with directional antennas.
Also note that the first two transmitter searches use the "auto-zoom" map camera feature, which will automatically zoom the screen to show both the vehicle and estimated transmitter location. The second half uses the standard free camera mode.
This is on a new build of the App which is currently in testing, so some things may look slightly different to the currently released version. The new app version will have some minor feature improvements.
KrakenSDR: Finding Multiple GSM Base Station Transmit Towers with the Multi-VFO Feature
TETRA (Terrestrial Trunked Radio) is a digital voice and text radio communications protocol often used by authorities and industry in European and many countries other than the USA. A major advantage to a digital communications protocol like TETRA is it's ability to be secured via encryption.
Recently the security researchers at Midnight Blue in the Netherlands have discovered a collection of five vulnerabilities collectively called "TETRA:BURST" and most of the five vulnerabilities apply to almost every TETRA network in the world. These two most critical vulnerabilities allow TETRA to be easily decrypted or attacked by consumer hardware.
The first critical vulnerability is designated CVE-2022-24401 is described as decryption oracle attack.
The Air Interface Encryption (AIE) keystream generator relies on the network time, which is publicly broadcast in an unauthenticated manner. This allows for decryption oracle attacks.
The second vulnerability CVE-2022-24402 notes that a backdoor has been built into TEA1 encrypted TETRA, which allows for a very easy brute force decryption.
The TEA1 algorithm has a backdoor that reduces the original 80-bit key to a key size which is trivially brute-forceable on consumer hardware in minutes.
Midnight Blue are due to release more technical details about the vulnerabilities on August 9 during the BlackHat security conference. Due to the sensitivity of the findings, the team have also held back on their findings for over 1.5 years, notifying as many affected parties as possible, and releasing recommended mitigations. It's unclear at the moment how many TETRA providers have implemented mitigations already.
For more detail about the possible implications the team write:
The issues of most immediate concern, especially to law enforcement and military users, are the decryption oracle and malleability attacks (CVE-2022-24401 and CVE-2022-24404) which allow for interception and malicious message injection against all non-E2EE protected traffic regardless of which TEA cipher is used. This could allow high-end adversaries to intercept or manipulate law enforcement and military radio communications.
The second issue of immediate concern, especially for critical infrastructure operators who do not use national emergency services TETRA networks, is the TEA1 backdoor (CVE-2022-24402) which constitutes a full break of the cipher, allowing for interception or manipulation of radio traffic. By exploiting this issue, attackers can not only intercept radio communications of private security services at harbors, airports, and railways but can also inject data traffic used for monitoring and control of industrial equipment. As an example, electrical substations can wrap telecontrol protocols in encrypted TETRA to have SCADA systems communicate with Remote Terminal Units (RTUs) over a Wide-area Network (WAN). Decrypting this traffic and injecting malicious traffic allows an attacker to potentially perform dangerous actions such as opening circuit breakers in electrical substations or manipulate railway signalling messages.
The deanonymization issue (CVE-2022-24403) is primarily relevant in a counter-intelligence context, where it enables low-cost monitoring of TETRA users and their movements in order to allow a state or criminal adversary to avoid covert observation or serve as an early warning of impending intervention by special forces.
Finally, the DCK pinning attack (CVE-2022-24400) does not allow for a full MitM attack but does allow for uplink interception as well as access to post-authentication protocol functionality.
Below is a demonstration of the TEA1 CVE-2022-24402 attack on TETRA, and if you are interested the Midnight Blue YouTube channel also contains a video demonstration for the CVE-2022-24401 decryption oracle attack.
Currently, it is possible to decode unencrypted TETRA using an RTL-SDR with software like TETRA-Kit, SDR# TETRA Plugin, WinTelive, and Telive. In the video the research team appear to use Telive as part of their work.
We also note that in the past we've run several stories about Dejan Ornig, a Slovenian researcher who was almost jailed because of his research into TETRA. Dejan's research was much simpler, as he simply discovered that many Police radios in his country had authentication turned off, when it should have been on.
Back in July 2021 we posted about the RadioBerry HF SDR Transceiver Raspberry Pi Hat which is an open source project by PA3GSB. It is based on the AD9866 chip which gives it a 12-bit ADC with one RX and one TX channel, a maximum bandwidth of up to 384 kHz, and an operating frequency range of 0 to 30 MHz.
Because of FPGA component shortages, the device has been out of stock and stagnant for a long time. However, recently a new version has been released by well known SDR hardware cloner Justin Peng and is now available for sale on Aliexpress for US$155. As the design for this project is open source, Justin's new version is legal and he has released the redesigned open source files on his GitHub.
In his latest video, Matt from the TechMinds YouTube channel tests out this new board. He starts by explaining the history of the RadioBerry, and shows how to set it up and install the software. He goes on to demonstrate it receiving some HF signals, transmitting on 3 kHz and 5 kHz, and how to run it standalone on a Raspberry Pi 4 with screen.
Over on his YouTube channel Mark Jessop has uploaded some dash cam footage showing him using a KrakenSDR and a custom LED display to hunt down three amateur radio transmitters during a fox-hunt.
An amateur radio fox-hunt is an activity where someone will hide a transmitter within a defined area, and it is up to the hunters to use radio direction finding equipment to find it. The KrakenSDR is our 5-channel coherent radio based on RTL-SDRs, and it can be used for applications like radio direction finding.
Mark uses a custom four element array on the roof of his car, which is connected to his KrakenSDR. Instead of the KrakenSDR app, Mark prefers to use his custom LED HUD to displays the bearings and signal power directly.
Some annotated and sped-up dash-cam footage captured during the July 2023 Amateur Radio Experimenters Group Fox-hunt. We run these monthly, and usually have three transmitters hidden around the Adelaide (South Australia) area.
I run a KrakenSDR with a custom-built 4-element antenna array mounted to the roof of my car. This gives me direction estimates to the target transmitter, at least when the signals are strong enough!
Thank you to Carl Reinemann (aka USRadioGuy) for letting us know through his blog post that goestools has recently been ported to Windows. Goestools is a software package that is used to receive and decode images from GOES weather satellites. In the past it was only available for Linux systems, however recently thanks to the work of Jamie Vital, goestools has now been ported and can run on Windows. Carl Reinemann has confirmed that the software runs perfectly on Windows. Our GOES tutorial should also be easily modified to work with the Windows port.
The Windows port can be downloaded from goestools-win on GitHub. If you are interested, Jamie Vital is also the author of Vitality GOES, which is a program that can display the received weather images in a nice GUI.
Alternatively we note that another cross platform GOES decoder is SatDump which is currently the most popular choice for GOES.
Over on his YouTube channel dereksgc has uploaded the next video in his series on satellite reception. In this video he shows how to build a Yagi antenna tuned for 137 MHz, which is great for receiving NOAA APT and Meteor M2-3 LRPT. Note that a Yagi antenna will give you stronger reception compared to a turnstile, QFH or V-Dipole, but as it is a directional antenna you will need to manually point it towards the satellite as it passes over your location.
For Meteor M2-3 LRPT, a Yagi antenna may be beneficial, as it appears this satellite is having some issues with signal strength, due to a possibly defective antenna that did not fully unfold on the satellite.
The Yagi antenna design is a four element design, with one reflector, two directors and one driven dipole element. The physical construction consists of a piece of wood for the boom, brass welding rods for the elements, and a terminal block for the active dipole element. 3D printed handles are added for easy holding and the RTL-SDR and LNA sit directly on top of the boom.
Thank you to Stéfane Perraud, Aram Kebabdjian and team for submitting news that they have recently launched an art project in Lausanne, Switzerland called "Hystérésia". The installation is technical art, which consists of an autonomous satellite receiving station designed to receive beacons from old "zombie" satellites, and then broadcast their signals audibly. A description of the ground station can be seen here.
Zombie or Dead satellites are satellites that are officially decommissioned and powered down, but have unintentionally reactivated. This often happens as over time the batteries on these satellites can undertake a chemical reaction from thousands of solar recharge cycles which eventually results in a short circuit. Hence the satellites reactivate when in sunlight. If you are interested we have an old post on this phenomena back from 2014.
The system is based on an antenna rotator with two Yagi's that tracks the zombie satellites as they pass over the sky. A QFH antenna has also been spotted in their images. Based on the waterfall images, an SDRplay RSP is used as the receiver, and some computing device is used to demodulate the signal into audio. Stefan adds:
Technically we are using a double yagi 137 and 145 plus a 777 antenna from diamond to catch 200 mHz
We developed a python based software that’s controlling a sdr software based on gnu radio.
We update TLE everyday, our azimuth and élévation rotor follow the satellites and we catch the signal with a sdr uno, plus a switch that choose antenna with the good satellite.
The machine is monitored by a bench of sensors , wind, humidity, temp. It can be control by internet via the website
The machine search for peaks around the chosen frequency, Also the sound is processed by max/msp, we denoise it and we make music out of it
The 3 metallics pavillons blows the sound noise to the audience Each time a satellite shows up, the machine sends a story told by one of our recording, a woman actors voice , it tells a specific history that’s tells a narrative about the satellite that’s on air … but in French
If you are unable to visit the installation in person, it appears that their website also broadcasts the last received satellite's sound. The website also shows photos of the history of the zombie satellites.
If you're interested in other art based on satellites and software defined radios, have a look at our previous post on the open weather project, and the "signs of life" project. Another SDR art project was 'Holypager', an art installation that continuously prints out pager messages received by a HackRF, and "ghosts in the air glow" project which used the HAARP antenna array to broadcast an art project.
Back in April we posted about the RFNM, an upcoming software defined radio project which will have eight 12-bit ADCs, up to 612 MHz real time bandwidth, and two DACs for transmitting with up to 153 MHz bandwidth. The standard board will support tuning from 600 - 7200 MHz, with tuning expanded down to 10 MHz via an RFFC2071A mixer.
They also updated their pricing, noting that they have upgraded a few specifications. The motherboard is set to be priced at $299. It will be available for preorder in August, with an expected October delivery date.
