Wow, this thread has gone really off topic :) But I figure I'd add in my 2c. A GSM Data call can carry up to 9.6kb/s. Using a good voice codec like Speex, one can get voice still sounding decent at 2kb/s. I don't really know much about the inner workings of GSM, but is there anything stopping one Neo from establishing a data link with another via CSD, then using netcat or something to simply pipe audio from the microphone into speex and then into a command line blowfish / twofish or whatever encryption you want, then on the other side do the same, but in reverse.
I have actually done what I mentioned above (Mic -> Speex -> Encrypt -> Comm -> Decrypt -> Speex -> Speaker) on my computer using some simple python scripts, and it works fine. The major issue IMO would be getting it from one point to another. Cheers Federico PS) I probably don't know what I'm talking about, eat with a pinch of salt. On 9/7/07, Mikko Rauhala <[EMAIL PROTECTED]> wrote: > pe, 2007-09-07 kello 13:35 -0700, Shawn Rutledge kirjoitti: > > It's easy to think first of doing it over a data connection. But I > > can imagine more of a signal-processing approach. > > This has been hashed to death. Short of it: the GSM codec actively tries > to throw away anything that doesn't sound like speech. This is not very > analog encryption friendly, and we can't bypass the codec for voice > calls since that's in the closed TI firmware. > > This is also a repeat, but for new people, I'll mention that > cryptophone.de does a proprietary encryption-capable GSM phone (through > GSM data); though the protocol is their own, they apparently have it > documented, and welcome others to do compatible implementations. (Their > source is also available, but for purely review and verification > purposes; it's not free and anyone doing a reimplementation would be > wise to avoid looking at it.) Thus for anyone interested in doing > encrypted calls with the Neo, it would perhaps be worth considering > using their ready-made protocol to leverage their installed base. > > I haven't reviewed their protocol though, nor am I highly qualified to > do that. Also, there's the usual potential future issues with the > protocol being controlled by a single firm; basically that's just > something to consider for those who eventually get hacking on this. > Sadly, it's too big a project for me. > > -- > Mikko Rauhala - [EMAIL PROTECTED] - <URL:http://www.iki.fi/mjr/> > Transhumanist - WTA member - <URL:http://www.transhumanism.org/> > Singularitarian - SIAI supporter - <URL:http://www.singinst.org/> > > > _______________________________________________ > OpenMoko community mailing list > [email protected] > http://lists.openmoko.org/mailman/listinfo/community > _______________________________________________ OpenMoko community mailing list [email protected] http://lists.openmoko.org/mailman/listinfo/community
