All these problems, like hiding the transfer amount , and anonymization, etc were solved (*) by my Appecoin protocol.
Appecoin proofs are relatively small, and fast to verify.
The fact that I didn't publish it (for a year) is that I still have moral doubts of enabling a completely anonymous payment system. Somebody has to proof that the benefit of such system outweigh the costs of its illegal use.
I hope Adam you're sure that you solved that dilemma when you finally build your own protocol.
(*) This is not completely true, since my paper has received little peer review, it might contain mistakes.
I hope your understanding of cryptography is better than your understanding of morality.
Ouch .... but it crossed my mind also.
So Sergio are you ever going to publish? Have you looked at the arguments regarding fungibility? If you truly have an idea that is possibly the best money humanity can have, the enormous economic benefits alone far outweigh any moral quandaries provide by a few errant users of the money (who, after all, have to answer to their God and their peers ultimately for their actions whatever the medium is that they choose to perpetrate them with).