Which blind signature schemes exist, and how do they compare?
I'm still a newbie in the field, but trying to learn something about it I ran into these two papers that you surely know, in case not I'll point them out:


Blind signatures for untraceable payments, Chaum
Provably secure blind signatures schemes, Pointcheval


By the way if you look at the introduction of the second title it seems what your looking for.



A specific link on Electronic Cash from RSA Laboratories:


What is Electronic Money




By studying blind signatures I've read about a scheme based on ElGamal Signature Scheme, I'll provide the information I was able to glimpse.

You can find more details at the following links:


IEEE, A blind signature scheme based on ElGamal signature
Citeseerx, Generalized blind signature schemes


Blinded ElGamal:


Performances:



  Owner Alice needs to compute two online exponentiations modulo $p$
  with a |$q$| bit exponent and one offline inverse modulo $q$.
  
  Notary Nancy needs to compute just one online exponentiations modulo
  $p$ with a |$q$| bit exponent.
  
  Verifier Victor needs to compute two exponentiations instead of the
  three ones required for standard ElGamal scheme.


Note: you can find further references for even more efficient variants in the links I provided.


Patents:


I have no clue!Sorry about that...


Simplicity:


I got it all clear, if reading the papers you have any doubts post them and we can check together!