https://www.kickstarter.com/projects/moonbaseotago/onerng-an-open-source-entropy-generator https://www.kickstarter.com/projects/moonbaseotago/onerng-an... It's

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.