A young researcher named Evangelos Bitsikas has found a way that bad guys could find out where you are by using text messages.
Evangelos is working on his Ph.D. degree at Northeastern University.
He and his team have found out about this problem by using a very advanced computer program on data from old-style text messaging, which we have been using since the early 90s.
They put their work on a website called arXiv before officially presenting it at a big security conference.
Evangelos says that if a person knows your phone number and has regular network access, they can find where you are. He is talking about people being tracked anywhere in the world.
Here’s how it works: When you get a text, your phone sends a kind of ‘message received’ signal back to the sender.
Now, if a bad person keeps sending texts to your phone, they can use the timing of these ‘message received’ signals to guess your location, even if you’re using secret codes for your messages.
Evangelos and his team used a smart computer program to learn this from the timing of the ‘message received’ signals. Once this is set up, a bad person can send a few text messages to a phone. The timing of the ‘message received’ signals is fed into the program, which then guesses the location.
For now, this only seems to be a problem for phones using the Android system, and it doesn’t seem like anyone is actually using this trick yet. However, Evangelos warns that it could be used in the future.
Getting this to work is hard because you would need to have many Android devices sending messages all the time and working out the timings. It could take a long time to collect all the data, and the computer program that does the learning is also tricky to set up.
The worry is that this could be used by rich and powerful groups to find out where important people are, like government leaders, activists, or big company bosses who want to keep their location secret.
Evangelos has shared his findings with a big global group called GSMA that looks after mobile networks.
They agreed that it’s a tough problem to solve, because it would mean making big changes to the way text messages work all over the world. GSMA is looking into ways to make this trick harder to pull off, but they can’t completely stop it.
Evangelos is now planning more research to build on what he’s found.
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Source: Northeastern University.
