[OTR-dev] Thinking about mpOTR and secure multiparty chat protocols in general

[Ileana]

On Thu, 21 Feb 2013 20:30:53 +0200
George Kadianakis <desnacked at riseup.net> wrote:

> Greetings,
> 
> this is a post about mpOTR and secure multiparty chat protocols in
> general. I'm very interested in the secure multiparty chat problem,
> and I _really_ want to see it moving forward.
[snip]
> * Based on the previous question, how much do we want the protocol to
>   scale? Do we want 5 people to be able to talk to each other, what
>   about 40? What about 200 people or even 1000?

As an aside question, 

About DH for multiple party, doesn't that require g^x g^y... g^xy

calculation of g^[n factors] where n is the number of chat
participants...so isn't the complexity exponential in the number of
chatters?  So the number of chatters is dependent on the amount of
processing power of the computations?  And still trying to retain
sufficient crypto strength of the parameters.  In other words, it seems
the cap is computationally capped at some point.

Correct me if I am wrong.

Ileana