I've been reading up on blind signatures and am trying to wrap my head around the concept - specifically in the context of anonymous blockchain transactions using vouchers. One particular issue I'm having with this is understanding what precisely a blind signature consists of. Do these differ from signatures of hashed values?
Would the following qualify as a blind signature:
Someone (A) hashes some data and signs it.
Hash sent to another party (B) who also signs it.
Data and hash and signatures are sent to yet another party (C) who can verify it all.
Or are they meant to mean that A creates data and blinds it, B signs the blinded data saying A created it and/or was authorized to do so, C receives blind signature and data without being able to relate it back to A - but by way of B can tell the data was created in a valid manner?
Is the objective just for C to never know who A is, but confirm that it was created in a valid manner via B?