Security 101

Courtesy:  Excerpt from  Tom’s Hardware

What would an operating system look like it if were redesigned with security in mind? Joanna Rutkowska thinks she has the answer with the development of Qubes OS. We sit down for an interview with Joanna to discuss the way Qubes OS augments security.

Alan: Since I know you’re busy, I’ll just throw in a link to our previous interview (Exclusive Interview: Going Three Levels Beyond Kernel Rootkits), in which you talked about the risks beyond the rootkit, and ask that our readers skim through it first.

I really want to get to talking about Qubes OS, though.

For the benefit of our audience, I want to review the three approaches to system security.

1) We have security by obscurity with things like memory randomization, obfuscating code, and system administrators mandating complex passwords. This acts as a first line of defense—if the bad guys can’t find your house, they can’t break in. It’s a deterrent that encourages the bad guys to look for an easier target. But it doesn’t work when they really want your data.

2) Then we have security by correctness, where software developers try to write bug-free code so that there are no vulnerabilities. Every time software gets patched, it’s a little bit more correct. But as we see every second Tuesday of the month, even the resources that Microsoft has are insufficient to come up with a perfectly correct OS. Modern software is so big and complex that it’s almost impossible to validate code to be perfect.

3) Finally, we have security by isolation, which takes a somewhat pessimistic (though more realistic) view that, at some point, the bad guys will break through whatever security measures you have, and so the focus should be stopping the bad guys from getting access to the rest of the system. Fair summary?

Joanna: Ha! I wish more interviewers were so well-prepared. 🙂

I would perhaps add to this one more category: 4) reactive security, which in practice comes down to: patches and signatures (for IDS and AV). Of course, this approach is the least effective, as we all well know…


One Comment Add yours

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