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We think that cosmic background radiation and certain subatomic mechanics are truly random. If you attach extra hardware to a computer, you can observe these an
by adrusi 11y ago
We think that cosmic background radiation and certain subatomic mechanics are truly random. If you attach extra hardware to a computer, you can observe these and send a stream of bits to the computer.
You don't usually want to use truly random numbers for cryptography though; /dev/random is more appropriate. I've never understood why, exactly, but that's generally the advice.
- witty_username 11y agoYou can use "truly" random numbers for cryptography. /dev/random is not recommended (except for perhaps long-term keys if you're worried about the randomness algorithms having a vulnerability), use /dev/urandom.
- atoponce 11y agoThere is no difference between /dev/random and /dev/urandom in the Linux kernel, other than /dev/random blocks when the entropy estimate is low or depleted. Both source them same CSPRNG, which is based on SHA-1. /dev/urandom is absolutely recommended for long-term keys.
- floatboth 11y ago> except for perhaps long-term keys On most systems, urandom and random are the exact same thing. Only Linux does this weird "blocking random" thing, based on some weird estimate of "running out of entropy" which is not an actual thing. (u)random is powered by a CSPRNG which is seeded by "truly random numbers" gathered from multiple hardware sources.
- maaku 11y agoCosmic background radiation as observed by a sensor connected to the computer is not random. All I'd need to mess with the randomness is to put a focused radiation source near the device. Sampling randomness from the environment surrounding the physical installation of the device is not good. I hope no one is doing this. There's no reason why you wouldn't want to use truly random numbers for cryptography. That's what /dev/random is supposed to provide.