Most wireless OEM hardware traditionally use 433MHz OOK modules to exchange information. The encoding and encryption of this data stream is left as a task for the embedded software designer. In most cases, the system can be hacked using a replay attack where an RF packet is recorded and replayed to emulate a valid user. [Gilad Fride] hacked his parking gate using this technique but decided to go the extra mile of connecting it to the internet.
He used an RTL-SDR dongle and ook-decoder by [jimstudt] to sniff out the gate code and this code was tested using an Arduino. The final implementation was done around an Onion Omega which talks directly to the RF transmitter module using the fast-gpio binary. Internet connectivity was achieved using Onion Cloud API which is used to trigger the execution of code thereby sending the gate opening signal.
[Gilad Fride] uses the IFTTT Do button to provide a GUI and he demonstrates this in action using an iPhone in the video below. The project can be extended to open garage doors or turn off the lights of your room over the internet.
If you are looking to hack your home security system, look no further as SDRs have be used to communicate with wireless products effectively in the past. We are hoping manufacturers take a hint and start using better encryption. Continue reading “SDR Sniffing Electric Gates”
In 1971, the United States Navy launched the Omega navigational system for submarines and surface ships. The system used radio frequencies and phase difference calculations to determine global position. A network of eight (VLF) transmitter sites spread around the globe made up the system, which required the cooperation of six other nations.
Omega’s fix accuracy was somewhere between one and two nautical miles. Her eight transmitter stations were positioned around the Earth such that any single point on the planet could receive a usable signal from at least five stations. All of the transmitters were synchronized to a Cesium clock and emitted signals on a time-shared schedule.
A ship’s receiving equipment performed navigation by comparing the phase difference between detected signals. This calculation was based around “lanes” that served to divvy up the distance between stations into equal divisions. A grid of these lanes formed by eight stations’ worth of overlapping signals provides intersecting lines of position (LOP) that give the sailor his fix.
In order for the lane numbers to have meaning, the sailor has to dial in his starting lane number in port based on the maps. He would then select the pair of stations nearest him, which were designated with the letters A to H. He would consult the skywave correction tables and make small adjustments for atmospheric conditions and other variances. Finally, he would set his lane number manually and set sail.
Continue reading “Retrotechtacular: The Omega Navigational System”