The Strange Story of Dual_EC_DRBG – suspected NSA backdoor (2007)
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Re: The Strange Story of Dual_EC_DRBG – suspected NSA backdoor (2007)
#2Great reading. Have you any idea how things evolved after that with those 4 proposed methods?
Re: The Strange Story of Dual_EC_DRBG – suspected NSA backdoor (2007)
#3Out of curiosity, why can't we just use a series of sensors on the computer to generate random numbers? Between mouse movements, touch inputs, video camera input, microphone movements, the behavior of applications in your system and how they use resources like RAM, CPU, hard-disk, listening to all the wifi + bluetooth signals around you and munging them, etc. I would imagine that there is enough entropy coming in through input and being generated by whatever the computer is doing to be able to have lots of unpredictable random numbers.
I don't know much at all about cryptography, but why aren't all the natural sources of entropy an adequate source of random numbers?
Re: The Strange Story of Dual_EC_DRBG – suspected NSA backdoor (2007)
#4Out of curiosity, why can't we just use a series of sensors on the computer to generate random numbers? Between mouse movements, touch inputs, video camera input, microphone movements, the behavior of applications in your system and how they use resources like RAM, CPU, hard-disk, listening to all the wifi + bluetooth signals around you and munging them, etc. I would imagine that there is enough entropy coming in thr…
I'm not sure if its still that way but I know PGP used to do that on Windows 95/98. You would have to move your mouse around in a window until it generated enough entropy to generate your key. I'm pretty sure I've seen it in either ssh keygen or openssl stuff also but that might have been in a virtual machine/jail with a poor or missing /dev/random.
Also I believe that is where /dev/random might get some of its information from, but I'm not too sure.
Re: The Strange Story of Dual_EC_DRBG – suspected NSA backdoor (2007)
#5Out of curiosity, why can't we just use a series of sensors on the computer to generate random numbers? Between mouse movements, touch inputs, video camera input, microphone movements, the behavior of applications in your system and how they use resources like RAM, CPU, hard-disk, listening to all the wifi + bluetooth signals around you and munging them, etc. I would imagine that there is enough entropy coming in thr…
I believe that, at least in Linux, ACPI thermal sensor readings are used for this purpose.
Re: The Strange Story of Dual_EC_DRBG – suspected NSA backdoor (2007)
#6So either the NSA wanted a backdoor, in which case we learn that even the NSA can't build a backdoor that academic cryptographers can't detect.
Or, much more likely I think, it was just a project that some NSA employees had sitting around and they wanted to get something out of it. In that case we learn that the NSA isn't so far ahead of academic cryptographers that their designs will always be better.
Either way I don't find this as scary a story as Schneier does.
Re: The Strange Story of Dual_EC_DRBG – suspected NSA backdoor (2007)
#7_NSAKEY discovered two years before patriot act is passed? coincidence? i think not!!1
said another way, what relates the two events in the editorialized title? Just an end of the innocence type vibe? Trusting the sigint guys to design your crypto has always been a well acknowledged double edged sword.
Re: The Strange Story of Dual_EC_DRBG – suspected NSA backdoor (2007)
#8Out of curiosity, why can't we just use a series of sensors on the computer to generate random numbers? Between mouse movements, touch inputs, video camera input, microphone movements, the behavior of applications in your system and how they use resources like RAM, CPU, hard-disk, listening to all the wifi + bluetooth signals around you and munging them, etc. I would imagine that there is enough entropy coming in thr…
I don't think that application behavior would be a good source of entropy, since it is, at least in theory, predictable. The others are probably good, although you need to be sure to only use the least significant bits, and make sure that the sensor doesn't have some weird behavior which makes the least significant bits predictable somehow.
If I had to hazard a guess, I'd say that this isn't often done simply because computers didn't typically have a lot of sensors until recently, and now you're likely to have a good-quality dedicated hardware random number generator built in, e.g. Intel's RDRAND instruction.
Re: The Strange Story of Dual_EC_DRBG – suspected NSA backdoor (2007)
#9Out of curiosity, why can't we just use a series of sensors on the computer to generate random numbers? Between mouse movements, touch inputs, video camera input, microphone movements, the behavior of applications in your system and how they use resources like RAM, CPU, hard-disk, listening to all the wifi + bluetooth signals around you and munging them, etc. I would imagine that there is enough entropy coming in thr…
This sort of thing is used, e.g. [0].
It collects entropy at a limited rate, though, so for demanding applications (SSL servers, say) you want dedicated hardware: [1], [2].
[0]: https://en.wikipedia.org/wiki/Hardware_random_number_generat...
Re: The Strange Story of Dual_EC_DRBG – suspected NSA backdoor (2007)
#10Out of curiosity, why can't we just use a series of sensors on the computer to generate random numbers? Between mouse movements, touch inputs, video camera input, microphone movements, the behavior of applications in your system and how they use resources like RAM, CPU, hard-disk, listening to all the wifi + bluetooth signals around you and munging them, etc. I would imagine that there is enough entropy coming in thr…
Every time you do a Diffie-Hellman key exchange you need to generate a random number. Which includes any time you open an https connection.
A busy webserver does this much more often than it can easily generate entropy for. So you have to take shortcuts. That's where a pseudo-random number generator comes in.