anonymity on multi-user systems
 

I work on multi-user systems pretty often, mostly in school or in the library, and I just wonder, how anonymous my sessions are?
I mean, is it possible for the root (or perhaps other users) to see what I'm typing in the shell, or see my browsing history? How do I know that they're able to do that? How can I protect myself?

P.S.: I'm curious not paranoid :)

Your question is not on anonymity, but privacy.

The only way to protect yourself from root on your local system is to use an encrypted tunnel to another system. But you have the same problem there: root on that system can see anything you do. They can see what you type in the shell if they want badly enough or they can just look in your shell's history file. For browsing they can just copy your browser caches and other files which aren't encrypted and even if they're encrypted, while you're using them they're unencrypted to you and to root.

How can you protect yourself? Run your own system and point all your browser caches to encrypted file containers, use SSL for email, encrypt all your email, etc. Then use your local multiuser system to SSH to your own, secure system. You'll have to learn to use console and command line apps because getting a remote X running requires bits you'll not be likely to have access to on a typical shared system. If you set up your own system you'll be able to have secure text browsing and email and messenger etc from console apps.

If you want anonymity you have to be more creative than that. First learn about securing and privacy and then work up to anonymity.

Even paranoids have real enemies. :)

It is possible to track keystrokes and there are threads here about this. The root user can certainly view your shell history file, your browsing history, etc. (anything at all in fact). The short answer is that you can't stop that access by the root user.

What can you do about it?

Apart from taking RanduxII's advice to protect your privacy:

- Make sure you stick to the acceptable usage policy so they're not going to find anything that will cause you problems;
- Write a script to delete history type files/caches and have it run from ~/.bash_logout