Researchers at University of Washington have come up with a solution to fight against police hacking you might not even know is happening. This system, called SeaGlass, can detect which cell tower signals may not be cell towers, but spoof signals set up by police to trick your phone into connecting to them.
IMSI-catchers, which spoof cell towers in order to intercept cellular signals and communication, are a tool of law enforcement that most people have no idea exist. International Mobile Subscriber Identity catchers, also known as Stingrays, send a signal that mimics a cell tower’s in order to encourage your cell phone to connect to it.
When you begin sending messages through this signal, law enforcement can collect your texts and calls, monitoring you in secret.
Widely criticized for appearing to violate basic privacy rules, the IMSI-catchers are nevertheless a popular tool among law enforcement officers, and few regulations appear to exist to protect people from these machines.
The University of Washington researchers, however, have developed a system by which they can collect offshore signals using a marine signal booster, then use an algorithm to detect which ones are probably IMSI signals. SeaGlass was tested for two months between Seattle, Washington and Milwaukee, Wisconsin, using rideshares to collect millions of data units over the time period.
According to Peter Ney, a researcher on the UW team, SeaGlass exists to collect more data and engender further research on our understanding of IMSI-catcher technology.
“Up until now the use of IMSI-catchers around the world has been shrouded in mystery, and this lack of concrete information is a barrier to informed public discussion. Having additional, independent and credible sources of information on cell-site simulators is critical to understanding how – and how responsibly – they are being used,” he said in a UW news release.
By detecting anomalies in the system, SeaGlass can identify when and where IMSI technology is being used, which can help the public understand who law enforcement is targeting and when they are employing the technology.
One particular data point UW researchers collected appeared to identify a potential IMSI-Catcher being used by or near an immigration services office, suggesting law enforcement are using it to track down undocumented immigrants.