edit 11/4/2015: rough outline to completion- probably have time to finish missing parts of the above draft within the next week or so, then over the next month or so hopefully clean it up for a ledger submission, code it in python, create C++ test suite, and finally code into the c++. I have a bit of unrelated (but important to me) research I am working on, so that is what has been taking my time since the original posting.

edit 11/11/2015: missing parts of above draft (still needs some typo checking etc and cleaning up and adding some exposition). http://eprint.iacr.org/2015/1098