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Can My School Tell I’m Using Tor?

Question: Will my school know if I use Tor at school?


Will they? There’s no way to know. It depends on how closely they’re looking.

Can they? Absolutely.

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TOR: The Onion Router

TOR, or The Onion Router, is a combination of software and servers that performs two important tasks:

  • An onionIt prevents the sites you visit from seeing where you’re coming from, and
  • It prevents the internet infrastructure, such as your ISP, from seeing what sites you visit (or what data you exchange with those sites).

The first point is a particularly important aspect of maintaining privacy or anonymity. It’s not the only aspect, to be sure — you can be identified in other ways, so it’s important to behave appropriately when attempting to maintain anonymity.

The second point is a side effect of the encryption involved. While a VPN protects your connection to the VPN service and not beyond, TOR encrypts and obfuscates the connection until immediately prior to the connection to the server or service you’re using.

Your school as your ISP

In providing your internet access, your school (or employer, or hotel, or wherever you might be) owns the networking equipment to which you connect. That equipment — typically one or more routers of various sorts — can do either or both of two things:

  • Monitor the traffic that flows across it
  • Send a copy of all traffic to another device that can monitor it

By “monitor”, I mean the equipment can watch for a variety of things and act based on what it finds. For instance, it could block access to known porn sites. A more complex example would be watching for and reporting downloads of known copyrighted files.

Watching for TOR

When you connect to TOR, you are connecting to one of several known entry points to the TOR network.

By monitoring the traffic across their network, the school can notice this, and thus see

  1. that someone is connecting to a TOR entry node, and
  2. which computer on their local network is doing so: your computer.

So absolutely, they can see that you’re using TOR. They can’t see what you’re connecting to through TOR, but they can see that you’re using it.

Now, will they notice?

Big brother, are you watching?

There’s no way to know.

It depends on many factors, including the technical expertise of whoever set up the network, whether they set it up for monitoring, and whether they actively watch for someone using Tor.

My guess is that most school personnel are so overworked to begin with that they don’t bother. At best, I’d guess they’ll probably configure the equipment to try to block your ability to access the Tor network, and leave it at that. Only if they’re informed that something suspicious is going on might they take a more active interest and monitor more closely.

Here’s the catch: you can’t count on that.

You can’t tell if they’re watching, so you can only assume that they’re watching.

Because they can.

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5 comments on “Can My School Tell I’m Using Tor?”

  1. “I’d guess they’ll probably configure the equipment to try to block your ability to access the Tor network”

    If that’s the case, how is it possible for people in China and other repressive countries use TOR to circumvent the Great Firewall of China? Wouldn’t they be able to block that?

    • I believe they do try. But it’s also a game of whack-a-mole with new TOR servers coming on line all the time, and potentially using ports (like port 80) which simply cannot be blocked for the rest of the internet to work properly.

  2. Leo, you said, “Big brother, are you watching?
    There’s no way to know.”

    Don’t be silly, Leo, of course there is. If your correspondent gets some sort of reprimand from his school for attempting anonymous browsing… well, that means that they were watching. :(

    Or, again, if he finds his TOR access blocked… well, that, too, means they were watching (albeit probably via an algorithm rather than by snooping personnel). :(

    The catch here, of course, is that if anyone is to know that their ISP has been been monitoring them, the ISP has to “let on” about it in some way. That said, unless the ISP intends to take some sort of action based upon their monitoring, it’s kinda hard to see why they would bother to monitor anyone’s online activities in the first place.

    • Well, obviously, if something happens that tells you they’re monitoring.

      However if something doesn’t happen, that tells you nothing. They could be monitoring, and just haven’t acted yet, or they could not be monitoring. There’s no way to know.


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