silly[bad, don't do this] idea: tor hsdir block device
you're given around 50kb of data per descriptor, and the interior is encrypted so it can't be checked for validity. define some mapping from disk id, block id into a key then write the data there. you even have the ability to change a block
(side note: the design of "encrypt all the data with the public key" is really nice. doesn't hurt UX on lookup at all since you'd have the key anyways, and means no one can just discover .onion services that are uploaded to them.
"encrypt all data with a key determined by what a client would know anyways" is cool design (i.e. if you have a service that lets you look up user profiles from a username, instead of sending the username to the server, use hash1(username) as the lookup key, and hash2(username) as an encryption key. if username isn't high entropy that's not strong protection, but prevents just walking a whole ass user directory, at least.)

