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The Raspberry Pi’s Hardware Random Number Generator

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Re: The Raspberry Pi’s Hardware Random Number Generator

#32
Here is my proposed RNG for network devices that don't generate much entropy of their own:

  strace -Tiv -ttt nice curl -Lv --raw $URL 2>&1 | shasum | dd bs=1 count=2 2>/dev/null
Possible values of $URL might be https://news.google.com, https://en.wikipedia.org/wiki/Special:Random, or the Twitter Firehose. :)

Re: The Raspberry Pi’s Hardware Random Number Generator

#33

Here is my proposed RNG for network devices that don't generate much entropy of their own: strace -Tiv -ttt nice curl -Lv --raw $URL 2>&1 | shasum | dd bs=1 count=2 2>/dev/null Possible values of $URL might be https://news.google.com , https://en.wikipedia.org/wiki/Special:Random , or the Twitter Firehose. :)

If you are connected to the internet, why not get your randomness from http://www.random.org/ ?

Re: The Raspberry Pi’s Hardware Random Number Generator

#34

The article is a bit vague about what exactly they're trying to say. What was unexpected? I read it three times before I decided they're comparing a lousy homegrown software RNG to the Pi's hardware RNG, which turns out to be good. Yes? Why would that be unexpected?

The way I read it was that it is surprising that it is there at all. Apparently a lot of android devices don't have one, and don't have time to collect pseudo random data for their software rng to make secure certificates when you boot it for the first time, which posses a security risk for android devices. That's how I read the article in relation to recent news.

Actually most ARM processors do have a hardware RNG, just that few companies write a driver for them

Re: The Raspberry Pi’s Hardware Random Number Generator

#35
post #30

Earlier quoted context omitted.

Here are the NIST recommendations referenced in the FIPS 140-2 approved RNG appendix: http://csrc.nist.gov/publications/nistpubs/800-90A/SP800-90A...

Thank you. For the last few days, I've been looking for the The NIST Statistical Test Suite, not in C#, have you a link?

Sorry, I just found the above from a quick google search for "FIPS 140-2 rng" which I noticed referenced in the rngtester output in the article.

Re: The Raspberry Pi’s Hardware Random Number Generator

#36
post #5

Perhaps this is a new application for the pi? A dedicated entropy appliance could be useful

Heh, there was a company that offered just such a beast, basically a network socket and an API to fetch a random number. I thought it was a really subtle joke (like that time I carried around a Diet Coke as my Halloween costume) but once people connected the dots between "Ok, you care so much about a cryptographically secure random number generator you buy an appliance that does nothing else, and then you talk to it…

You'd use radioactive decay:

http://www.fourmilab.ch/hotbits/

You could probably do it with the radioactive source in a smoke detector.

Re: The Raspberry Pi’s Hardware Random Number Generator

#37
post #7

It may well be that small hardware could be better for generating keys, as it is much easier to audit the total system, and I'd trust it more than an Intel processor with known remote patching capabilities. If you're security-sensitive then it could be good having a small, dedicated system like the Pi, and make sure that your private key never leaves it.

If you don't trust a chip vendor's remote patching, there's nothing you can trust on the chip cryptographically at all.

Re: The Raspberry Pi’s Hardware Random Number Generator

#38
post #21
post #3

What barriers keep thermal random number generators from being widely available? Or are they actually?

Sometimes they're not very good. Sometimes they're just very expensive. There are a range of different hardware devices available on various plugin boards. And processors have started to include them as well. Here's a very old (1997?) examination of 3 hardware devices: ( http://www.robertnz.net/true_rng.html ) and he has some nice information here too: ( http://www.robertnz.net/hwrng.htm ) Here's my list of recent re…

Thanks, very helpful.

Re: The Raspberry Pi’s Hardware Random Number Generator

#40

The article is a bit vague about what exactly they're trying to say. What was unexpected? I read it three times before I decided they're comparing a lousy homegrown software RNG to the Pi's hardware RNG, which turns out to be good. Yes? Why would that be unexpected?

The impression I got was that the existence of a hardware random number generator was unexpected.

The rest was just demonstrating that it works, and produces pretty reliable random output. In order to do that, they used a standard tool that tests randomness. But it's nice to make sure your randomness test tool is actually good; so using it on a known-bad RNG, and seeing that it does fail, is a good way to demonstrate that.

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