If it's like that, then a simple amplitude-modulation over a pre-recorded, fixed, carrier of the encrypted data should be no problem, since amplitudes are sent...
On Sat, Apr 26, 2008 at 12:09 AM, Flemming Richter Mikkelsen <[EMAIL PROTECTED]> wrote: > On 4/24/08, ramsesoriginal <[EMAIL PROTECTED]> wrote: > > On Thu, Apr 24, 2008 at 2:47 PM, Adilson Oliveira > > > > - - I've being reading about a project to implement cryptography on > > > Openmoko so the calls and text messages can be secured, unfortunately I > > > forgot the name of the project but I've heard that voice calls can't be > > > secured like that due limitations on the way GSM work. Is this correct? > > > > As far as I understood it, a GSoC-Project is a sms middleware, which > > should (theoretically) implement a way to simply encrypt with gpg the > > sms. Phone calls can't be encrypted that easilly because, as far as i > > understood it, the microphone is connected directly to the gsm chip. > > But we have many intelligent people here, so someone will probably > > find a way to do even that. > > The microphone is connected to the sound card:) > > The reason that encrypted calls over GSM is so difficult, is that the GSM > chip samples and encode the input from the microphone. This coding > is optimized for speach only and does not actually send your speach > over the network, but it breakes the sound up in small parts and > use a lookup table to find something that is more or less similar. > It then sends the table index over the network. The actual sound is never > sent, not even in digital form. This is at least how I remember it > > -- > Please don't send me Word or PowerPoint attachments. > See http://www.gnu.org/philosophy/no-word-attachments.html > > Join the FSF as an Associate Member at: > <URL:http://www.fsf.org/register_form?referrer=5774> > > Free your mind - Open(moko) your phone > > > > _______________________________________________ > Openmoko community mailing list > [email protected] > http://lists.openmoko.org/mailman/listinfo/community > -- My corner of the web: http://blog.ramsesoriginal.org _______________________________________________ Openmoko community mailing list [email protected] http://lists.openmoko.org/mailman/listinfo/community
