[andrewstellar]

> Another solution would be to allow gateways to declare that their coins are only redeemable by a limited set of accounts.

Yep, that's baked into the protocol :) https://www.stellar.org/api/#api-accountset - require Auth flag

[eridius]

Ah hah. I don't see any way to actually authorize an account to hold credit though. TrustSet seems to strictly be the reverse, and nothing else looks relevant.