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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

#11
post #6

A good number of Intel processors have hardware rngs. http://software.intel.com/en-us/articles/intel-digital-rando... Of course they're not on $35 boards, but the server machines you are using may already have this.

Intel's RDRAND is mentioned in the article as well, near the end. I suspect this article is doing so well because of the recent realization of Intel's involvement with the NSA, and the high potential for backdoors to be included in such a technology.

Re: The Raspberry Pi’s Hardware Random Number Generator

#12
post #8

Does anyone have a link for a spec for the RNG? Specifically, where does it get its entropy from? Couldn't find it in the source link. Only mention I could find is a vague mention of "thermal noise" which could mean anything.

I found the link on Reddit. They're asking similar questions.

So far Reddit hasn't got any answers; someone posted a link to a mailing list. Here's a similar link. (https://lkml.org/lkml/2013/3/24/144)

> This adds a driver for random number generator present on Broadcom BCM2835 SoC, used in Raspberry Pi and Roku 2 devices.

Here's a github for the blob source (https://github.com/raspberrypi/linux/blob/rpi-3.6.y/drivers/...)

It's a frustrating lack of information. :-/

(I posted here partly because of the Intel RdRand stuff the other day, but also RPis are fun and this could be a fun experiment.)

Re: The Raspberry Pi’s Hardware Random Number Generator

#13
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?

Re: The Raspberry Pi’s Hardware Random Number Generator

#15
post #12
post #8

Does anyone have a link for a spec for the RNG? Specifically, where does it get its entropy from? Couldn't find it in the source link. Only mention I could find is a vague mention of "thermal noise" which could mean anything.

I found the link on Reddit. They're asking similar questions. So far Reddit hasn't got any answers; someone posted a link to a mailing list. Here's a similar link. ( https://lkml.org/lkml/2013/3/24/144 ) > This adds a driver for random number generator present on Broadcom BCM2835 SoC, used in Raspberry Pi and Roku 2 devices. Here's a github for the blob source ( https://github.com/raspberrypi/linux/blob/rpi-3.6.y/dri…

The only use for a binary blob that purports to a be a secure RNG is to feed it to /dev/random.

Re: The Raspberry Pi’s Hardware Random Number Generator

#16
post #9

Do hw rng's get a test suite certificate(NIST's?), like a Swiss watch, or like a optical sextant's `Certificate of Errors'? Tables of mean, standard deviation, etc, for expected physical dependent parameters(what: speed? temp? ...)?

Here are the NIST recommendations referenced in the FIPS 140-2 approved RNG appendix:

http://csrc.nist.gov/publications/nistpubs/800-90A/SP800-90A...

Re: The Raspberry Pi’s Hardware Random Number Generator

#17

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.

Re: The Raspberry Pi’s Hardware Random Number Generator

#18
post #10

Is there a way to seed /dev/urandom and /dev/random from it?

Rng-tools [1], mentioned in the article, can use a hardware rng's output as input to the kernel's prng. However, it needs to be configured correctly to avoid potential problems [2].

[1] http://www.gnu.org/software/hurd/user/tlecarrour/rng-tools.h...

[2] https://news.ycombinator.com/item?id=6040975

Re: The Raspberry Pi’s Hardware Random Number Generator

#19
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…

Similar in spirit to SGI's Lavarand [1]

[1] http://web.archive.org/web/19971210213248/http://lavarand.sg...

Re: The Raspberry Pi’s Hardware Random Number Generator

#20
post #11
post #6

A good number of Intel processors have hardware rngs. http://software.intel.com/en-us/articles/intel-digital-rando... Of course they're not on $35 boards, but the server machines you are using may already have this.

Intel's RDRAND is mentioned in the article as well, near the end. I suspect this article is doing so well because of the recent realization of Intel's involvement with the NSA, and the high potential for backdoors to be included in such a technology.

Broadcom is a similarly huge USA company in ARM computers & networking, are we sure they haven't been involved with the NSA either?
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