5 ms·

tangential question; does anyone know of a cheap hardware random number generator for PCs. thanks.

bomdo 10y ago
https://www.kickstarter.com/projects/moonbaseotago/onerng-an-open-source-entropy-generator https://www.kickstarter.com/projects/moonbaseotago/onerng-an... It's a ~$50 USB dongle, opensource and available for shipping. Anecdotally, I personally used it for an RF project that need uniform randomness and exhausted /dev/random on the target hardware. It worked fine, if a bit slow for my very specific usecase. That said, if you want to go even cheaper, seriously consider if you can just stick with /dev/urandom. See http://www.2uo.de/myths-about-urandom/ http://www.2uo.de/myths-about-urandom/ for an interesting read on why that might just work.
Sami_Lehtinen 10y ago
Crappy (free, obsolete) webcam, fm-receiver, tv-receiver + sha512? - Define cheap.
- chrisseaton 10y ago
  I'm not normally a paranoid person but EM radiation seems like it's something that it would be easy for someone outside your house in a van to manipulate.
  - MichaelRenor 10y ago
    Discussions about random seed generators usually devolve into theoretical issues about why <random idea> can be manipulated. If you're really paranoid, just do this: $ echo "<bash face against keyboard multiple times>" >> /dev/random
  - Dylan16807 10y ago
    It should be basically impossible for them to manipulate the low bits of the signal. Then you hash it, which makes any bias irrelevant as long as enough bits are random.
imaginenore 10y ago
Shitty webcam. Take the least important bit of a random pixel of every 8x8 block of pixels.
nickpsecurity 10y ago
WaywardGeek built one on thermal noise that's on Tindie for about $35: https://github.com/waywardgeek/infnoise https://github.com/waywardgeek/infnoise https://www.tindie.com/products/WaywardGeek/infinite-noise-true-random-number-generator/ https://www.tindie.com/products/WaywardGeek/infinite-noise-t... I remember him from the CipherShed project that was trying to reboot TrueCrypt. Discussed securing the build system & distribution. He seemed smart. I have no experience with Tindie, though, so I'd appreciate feedback from anyone that knows about them. He also includes BOM, etc on the GitHub so someone can source and build it themselves.
mnordhoff 10y ago
You realize modern Intel CPUs include a TRNG, with the RDRAND and RDSEED instructions, for no extra cost. Can't get cheaper than that, if you already have one. https://en.wikipedia.org/wiki/RdRand https://en.wikipedia.org/wiki/RdRand The potential of an NSA backdoor in it is a popular, and entirely possible, conspiracy theory, of course. You'd have to decide for yourself, and compare it to your trust in other options.

bomdo 10y ago

https://www.kickstarter.com/projects/moonbaseotago/onerng-an-open-source-entropy-generator https://www.kickstarter.com/projects/moonbaseotago/onerng-an... It's a ~$50 USB dongle, opensource and available for shipping. Anecdotally, I personally used it for an RF project that need uniform randomness and exhausted /dev/random on the target hardware. It worked fine, if a bit slow for my very specific usecase. That said, if you want to go even cheaper, seriously consider if you can just stick with /dev/urandom. See http://www.2uo.de/myths-about-urandom/ http://www.2uo.de/myths-about-urandom/ for an interesting read on why that might just work.

Sami_Lehtinen 10y ago

Crappy (free, obsolete) webcam, fm-receiver, tv-receiver + sha512? - Define cheap.

chrisseaton 10y ago
I'm not normally a paranoid person but EM radiation seems like it's something that it would be easy for someone outside your house in a van to manipulate.
- MichaelRenor 10y ago
  Discussions about random seed generators usually devolve into theoretical issues about why <random idea> can be manipulated. If you're really paranoid, just do this: $ echo "<bash face against keyboard multiple times>" >> /dev/random
- Dylan16807 10y ago
  It should be basically impossible for them to manipulate the low bits of the signal. Then you hash it, which makes any bias irrelevant as long as enough bits are random.

imaginenore 10y ago

Shitty webcam. Take the least important bit of a random pixel of every 8x8 block of pixels.

nickpsecurity 10y ago

WaywardGeek built one on thermal noise that's on Tindie for about $35: https://github.com/waywardgeek/infnoise https://github.com/waywardgeek/infnoise https://www.tindie.com/products/WaywardGeek/infinite-noise-true-random-number-generator/ https://www.tindie.com/products/WaywardGeek/infinite-noise-t... I remember him from the CipherShed project that was trying to reboot TrueCrypt. Discussed securing the build system & distribution. He seemed smart. I have no experience with Tindie, though, so I'd appreciate feedback from anyone that knows about them. He also includes BOM, etc on the GitHub so someone can source and build it themselves.

mnordhoff 10y ago

You realize modern Intel CPUs include a TRNG, with the RDRAND and RDSEED instructions, for no extra cost. Can't get cheaper than that, if you already have one. https://en.wikipedia.org/wiki/RdRand https://en.wikipedia.org/wiki/RdRand The potential of an NSA backdoor in it is a popular, and entirely possible, conspiracy theory, of course. You'd have to decide for yourself, and compare it to your trust in other options.