[dragontamer]

Alternatively, you can choose a proven source of white noise.

Such as the reverse-bias shot and/or avalanche noise at the pn junction of a reverse bias'ed Zener Diode. Which is white-noise into the hundreds-of-MHz. Maybe not good enough for RDSEED, but certainly good enough and fast-enough for most hobbyist projects who are experimenting with this for the first time.