Excellent dive: methodically clear, converging into lovely "ok, I got it" diagram, then applied use case examples.

Two year old typo:

In another bit of intriguing similarity, Common Crypto makes the same trio of corecryto calls as arc4random(3):

I think that /dev/u?random being implemented by Fortuna is actually incorrect, and the macOS manpages are wrong. My understanding is that it is using a NIST DRBG, there's a Craig Federighi tweet somewhere confirming this.

See: https://crypto.stackexchange.com/a/72221