P2P anonymization is tricky. Making it scalable means that each member of the network isn't aware of every other member, and therefore a small malicious set of peer may be able to "capture" the routes of nodes that only know them or rely on them to boostrap into the network. The most sophisticated current research proposals are probably ShadowWalker by Mittal and Borisov (https://netfiles.uiuc.edu/mittal2/www/shadowwalker-ccs09.pd) and Torsk by McLachlan et al. (www-users.cs.umn.edu/~hopper/torsk-ccs.pdf). They are both certainly less vulnerable than MorphMix, which anyway is designed for high-latency communication.