If you’ve ever wanted to explore using a hardware random number generator, Johannes Weber put together a thorough guide to get started. He used a cheap Raspberry Pi, which has a hardware random number generator on the SoC. He also explored using a software-defined radio dongle to use atmospheric noise for random number generation. He also weighted this against the cryptographically secure pseudorandom number generation source /dev/random. He tested the outputs with dieharder to judge the random number quality. All were to some degree successful. Johannes does a good job of documenting the difficulty to get each up and running, how well they perform, and what some of the use cases are for the numbers once generated.
Johannes Weber comments:
I have tested both of them with various options and ran them against the dieharder test suite. In this post I am listing the CLI commands to get the random data from those source and I am listing the results of the tests.
Read more at: Playing with Randomness