Hi, If you do not use BitFolk's Entropy service and have no interest in doing so then this email will be of little interest to you can be safely ignored. If you haven't heard about the Entropy service before, please see: https://tools.bitfolk.com/wiki/Entropy If you *do* use the Entropy service though, I'm interested to know what software you have that actually uses /dev/random (and not /dev/urandom). Some background to this question: To provide the Entropy service we use hardware entropy generators, currently exclusively a pair of EntropyKeys manufactured by a UK company called Simtec Electronics Ltd. Despite the fact that these were extremely popular little devices (compared to other fairly niche little gadgets), Simtec always had a supply problem and then Simtec imploded as a company, so as far as I know these are now impossible to obtain, the IP is lost forever etc. Although I have one spare EntropyKey ready to put in service should one of the two in service ever die (I've not experienced that yet), that left me slightly worried as to what I'd do if I needed to get more. Then I saw the OneRNG kickstarter, and decided to pledge. So now I have 5 of (the internal USB version of) these: http://onerng.info/ I've not yet gone any further than verifying that they keep the entropy pool full on the machine they're plugged into, but that's good enough for now. Could be a decade before one of my existing EntropyKeys dies. I have since heard that this device proved far more popular than its manufacturer expected (sense a theme?) and they're now extremely difficult to get hold of because they need to get a new batch made in China. I've had multiple people contacting me on the basis of a tweet I did about getting these, asking me to sell them mine (which I would, but they didn't want internal USB). The point I'm trying to make here is that the world of hardware random number generators is not one with reliable supply lines, unless you want to spend a fortune on some black box. So when I came across: http://www.2uo.de/myths-about-urandom/ I was sad that the nerdery that is the Entropy service may be misguided, but also happy with the possibility that I might never have to source a hardware RNG again. Let's just take the argument posited by the article, that all (Linux) software should just learn to love /dev/urandom¹, as true. If you don't agree with this claim, you are disagreeing with some pretty big names in crypto. The Hacker News commentary on the article may also prove of interest: https://news.ycombinator.com/item?id=10149019 At the very least, I feel the Entropy article on the BitFolk Wiki needs an update in light of this. To justify the service's existence, if nothing else. Going further, the question becomes, well, what software is there in existence that forces use of /dev/random with no configuration that would allow otherwise? Because even if we agree that all software *should* be using urandom, if some popular software *refuses* to without recompile, then we're still going to have to provide an Entropy service, because doing so is easier than running non-packaged software. So Entropy service users, what have you got that uses /dev/random? Cheers, Andy ¹ A more correct summary of it is probably, "urandom is fine all the time except for on initial boot when a small amount of entropy from outside the CSPRNG is desirable." On shutdown all fairly modern Linuxes save the current entropy pool to the filesystem and load it up from there on boot, so it's only essential on first boot. -- http://bitfolk.com/ -- No-nonsense VPS hosting