Crytped calls through 9600Baud GSM-data connections?

Robert Michel openmoko at
Fri Feb 2 20:58:29 CET 2007

Salve Paul!

Paul Wouters schrieb am Freitag, den 02. Februar 2007 um 20:43h:

> On Fri, 2 Feb 2007, Robert Michel wrote:
> > Did you discussed OTP, using less mobile device batterypower to add
> > to the voicestream to build an encrypted connection between on users
> > mobil and his homeserver?
> Nope. In general, devices these days have enough cpu power to just do
> AES. CPU isn't the limiting factor, latency and/or bandwith are. (for
> voice encryption at least)

CPU isn't maybe a limiting factor, I thought about the batterypower :)
And OTP would give an latency advantage as well. ;)

> > -would piping through such a connection possible without TCP or other
> >  overhead?
> If you do a gsm dat call, you can of course run your own protocol like
> cryptophone does. 

My question is, would it be possibe to run 2 low quality phone calls
via one GSM data connection with speex?
Or when not having a second phone call, the connection could be used
for data transmission.

> > PS: I made advertisement on this list for your presentation in Berlin,
> >     and that this video is no online - but good that mention that it
> >     is online again - it worth for the most here on the list to see it.
> I moved some files and removed the ASF file in favour of the mp4 file,
> since the ASF file caused a lot of problems for people to get to play.
But there are also other mirrors... see my mail and my downloadscript:


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