I added a proposal for an identity (account) and reputation system.
It is described in the paper here:
https://docs.google.com/document/d/1d3EiWZdaM89-P6MVhS53unXv2-pDpSFsN3W4kCGXKgY/edit?pli=1#heading=h.bnpc4r2eii0m

Any criticism/review welcome!