[dpifke]

I've used a small block cipher like Skip32 or Speck to obfuscate database sequences, either on INSERT or as part of the encoding scheme.

This works well against the German Tank Problem when there's no oracle allowing an attacker to guess lots of IDs quickly (such as when there are reasonable rate limits). It does not provide enough entropy when such an oracle exists (especially an offline one).

For something like a password reset token, it still needs to be paired with suitably random bytes.