Cosmic 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 radiat

Cosmic 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.