> Zenocoin argument stands. If you have access to the full bitcoin chain, can you write a mathematical proof that allows one account to transfer anonymously to

> Zenocoin argument stands. If you have access to the full bitcoin chain, can you write a mathematical proof that allows one account to transfer anonymously to another account, without using a "tumbler" mixed account? Surprisingly, yes: that's exactly the accomplishment of Zerocoin, though it's currently too inefficient to be practical. (It still requires many participants, but the "tumbling" is global and does not require any trusted pool.)