-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 On 12/03/14 20:42, Ximin Luo wrote: > However, in the mpOTR (and general group chat) setting, we have > dynamic groups, with the condition that new members should not see > previous messages[3].
Hi Ximin, Without casting any doubt on the value of pure research, I wonder if it might be worth considering whether the above condition is really needed. Not all group conversations have the property that new members can't see what happened before they joined - some mailing lists have private archives that any subscriber can access, for example, and I think I've heard that when you join a Facebook thread you can see the whole conversation so far. If it turns out that we can solve the problem of multi-party encrypted chat by sacrificing the property that new members can't see what happened before they joined, I personally think that's acceptable. As long as users understand what the privacy properties are, they'll be fine. I've recently been reading 'Distributed Systems for Fun and Profit', and the way it tells the history of distributed systems research is really interesting. According to this account there are decades of impossibility results and really complex algorithms trying to make distributed systems behave like single computers - and then about 15 years ago there's this second wave of research that asks, do we actually need those guarantees, or do we just need something that scales well enough and works reliably enough to run a business on top of? The emphasis shifts from making failures theoretically impossible to making them manageable - and there's an explosion of new ideas, and lo the Amazons and the Googles doth flourish. Anyway this is turning into a sermon, but here's the book - it's a good read even if you already know all this stuff (I didn't): http://book.mixu.net/distsys/ Cheers, Michael -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (GNU/Linux) iQEcBAEBCAAGBQJTQEeWAAoJEBEET9GfxSfMV8sH/jNaqbgJJf9yiXBxI5U2HjOv dl4UjtkpviZOx+GuVw5HN2RCQsd5e5d6TQoRb0xfroXt62rs9++NYQTrO0cEofS1 ApyESQxplCGFNR2RAtY3PsmM9i+5MlHMxHpnqdwcbNBXw/+j/hF30TgLSsRJCj2d ZisB0nxTaZCiSAl7ZhKTHry77fHoXtD0B+qAqnQ4yWOxQkP2HN4ckrpvCgfTTx0p yqHBFEaTOcPmKSgdSy08tUxWOIhb7XjXcnbWkM60tbLgRgIn3DR+6wA9gMeTakhE lllQuQhsqkbr/e0ZNEkLK0K3vdNc1lIcCUmecBkiI1gd6bgOZHGl3hIqI+nHj8I= =VfSi -----END PGP SIGNATURE----- _______________________________________________ Messaging mailing list [email protected] https://moderncrypto.org/mailman/listinfo/messaging
