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Linus on /dev/random: "We actually know what we are doing. You don't."

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Re: Linus on /dev/random: "We actually know what we are doing. You don't."

#11

Post by icecreampain »

antocv wrote: post #8
yeukhon wrote: post #2

I'd want to hear Linus responding to both the OP and Taylor. But quick thought: do people like Bruce Schneier ever read this file? I think in the next year or two we will see a huge number of research going into finding "backdoor", suggesting implementation weaknesses. I am not going to speculate too much about who is NSA mole or why certain code got into the codebase. I'm more interested in researchers to find more…

Bruce Schneier I have all the respect for the guy, really, but then I read his guardian article "how to keep your data safe and secure" and mentions keeping "air gap" between computers with sensitive data but then he himself admits after all his methods and safeguards for the leaks he is working with, he uses Windows and usb-sticks to transfer (encrypted) files between them. He uses Windows. He uses Windows. And he w…

Using [only] Windows should automatically disqualify one from giving and security related advice.

At least Linux and BSD source is viewable by people. Lots of people.

Re: Linus on /dev/random: "We actually know what we are doing. You don't."

#12

Post by hrjet »

icecreampain wrote: post #9

If you consider the title of the article, "Rudest man in Linuxdom", you understand very quickly that the article author is imposing their own moral on Linus, but that's OK because the author is a proven programming genius of greater skill than the person who invented Linux, git, etc. ... Oh wait, he isn't. The author of the article is just another "tech blogger" that is interested in page views. So what's more intere…

Regardless of how the author has presented his arguments, why don't _we_ focus on the actual arguments? This is getting rather too meta.

Also, what's the use of an open-source OS that is used by millions if it is shrouded in esoteric arguments? I would certainly like Linux developers to better express themselves even if _I_ can't build such a system myself.

Re: Linus on /dev/random: "We actually know what we are doing. You don't."

#15

Post by jpalomaki »

If I remember right, the original reasoning why this could be a problem was something along the lines:

You are using sources s1, s2, s3. Then final result is combination c(s1,s2,s3). Now somebody screws up something and the sources s1 and s2 start returning just constant values. If you were just using s1 and s2 you would immediately notice this. However since you are combining all three, you are getting something that looks good but what might not be really secure if the source s3 is compromised.

(I think this came up in some HN discussion some weeks ago)

I'm not familiar with the Linux implementation so I don't know if this has any meaning there.

Re: Linus on /dev/random: "We actually know what we are doing. You don't."

#16

Post by jacquesm »

This whole discussion about rdrand reminds me of people arguing about what strength the secondary lock on their upstairs back window should be when the downstairs floor has single pane glass windows all around.

Even if rdrand is backdoored it would have to be a significant supplier of entropy in the resulting random number for this to be a meaningful attack vector, as soon as you mix it with other (good enough, large enough) sources of entropy you get a situation where some other attack is more likely to be far more feasible than to use the knowledge about some of the bits that rdrand contributes to the entropy pool.

Such as:

  - good old b&e and placing a keylogger or hardware bug
    (very easy to hide in a keyboard)

  - a compromised bit of the OS

  - compromising the application that you use to encrypt your messages or finding a significant weakness in the application.

  - doing any of the above with the recipient

Re: Linus on /dev/random: "We actually know what we are doing. You don't."

#17

Post by jamesrom »

antocv wrote: post #8
yeukhon wrote: post #2

I'd want to hear Linus responding to both the OP and Taylor. But quick thought: do people like Bruce Schneier ever read this file? I think in the next year or two we will see a huge number of research going into finding "backdoor", suggesting implementation weaknesses. I am not going to speculate too much about who is NSA mole or why certain code got into the codebase. I'm more interested in researchers to find more…

Bruce Schneier I have all the respect for the guy, really, but then I read his guardian article "how to keep your data safe and secure" and mentions keeping "air gap" between computers with sensitive data but then he himself admits after all his methods and safeguards for the leaks he is working with, he uses Windows and usb-sticks to transfer (encrypted) files between them. He uses Windows. He uses Windows. And he w…

It's still good advice. In fact, unless you audit the source of your OS, it's compiler, hardware and any software you need to use you can't really make any guarantees either.

Re: Linus on /dev/random: "We actually know what we are doing. You don't."

#20

Post by antocv »

jamesrom wrote: post #17
antocv wrote: post #8

Earlier quoted context omitted.

Bruce Schneier I have all the respect for the guy, really, but then I read his guardian article "how to keep your data safe and secure" and mentions keeping "air gap" between computers with sensitive data but then he himself admits after all his methods and safeguards for the leaks he is working with, he uses Windows and usb-sticks to transfer (encrypted) files between them. He uses Windows. He uses Windows. And he w…

It's still good advice. In fact, unless you audit the source of your OS, it's compiler, hardware and any software you need to use you can't really make any guarantees either.

I can make you the guarantee that Microsoft is actively cooperating with the NSA and has backdoors in Windows.

I can guarantee you that few people have access to the Windows source to check it.

I can also guarantee you that many more people have access and have audited the source code of a GNU/Linux system.

I cant guarantee you that GNU/Linux doesnt have backdoors. But for all intents and purposes it is just plain Wrong to use windows for any security related activities.

Would you be more comfortable leaking documents using a GNU/Linux livecd or Windows?

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