Symon, excellent question. The overall ZKP architecture that Jason, Dmitry, and team have been following is based on the IDEMix architecture from Jan Camenisch at IBM Research. However Jason and Dmitry have innovated on top of that, particularly in the area of revocation.
I’ll have to leave the details to them to share (I don’t even play a cryptographer on TV ;-). Also, Jason may be offline for a spell after several weeks of travel. But I’m hoping another member of the Evernym dev team can step in with some details.