There is a lot said for making the Linux random number generator configurable. A good entropy (random number) source takes entropy from a number of different so

There is a lot said for making the Linux random number generator configurable. A good entropy (random number) source takes entropy from a number of different sources and combines it with a cryptographic strong algorithm: Either a strong hash whose output is made the key and IV for a stream cipher, or directly using an Extendable-Output Function (XOF) such as a cryptographic sponge. [1] For example, there is some controversy with the RDRAND (the x86 ”give me random bits” op code) operation, with concerns that maybe the numbers weren’t truly random, and at least one known security hole where the RDRAND output could leak under some circumstances. However, it’s widely available and probably makes good random bits. However, if it doesn’t, we want other sources of entropy (microphone output low bits, interrupt timings, etc.) so /dev/random or /dev/urandom still gives us strong entropy even if RDRAND is completely busted. [1] I personally think a cryptographic sponge is ideal for this, since sponge functions have absorb, output, and duplex (absorb after output, i.e. accept new entropy from the system after outputting bits) functionality