If you're talking about adding encryption to the standard GSM voice channel then I don't think it'll work for several reasons. The base station decrypts the voice data before passing it on, and who knows what it'll go through between there and the destination. Also the GSM module does all the processing for voice calls, so anything you can do will come before the stock compression and encryption.
If you're talking about making an encrypted VoIP then check the archives because it's been thoroughly discussed. There's a link to a video presentation on exactly that, including why the slow GSM data channel is better for voice than the faster GPRS Don't have an NY Times account. On Monday 02 July 2007 00:56, Patrick Madden wrote: > Hi -- I spotted a bit of discussion in the archives on this, but it > wasn't clear if it would be possible to add in alternate encryption > algorithms. > > I'd like to get access to the voice packets prior to them being sent > out. The flow I'm hoping to be able to achieve is > [speaker] -> [stock compression] -> [MY ENCRYPT] -> cell network -> > [MY DECRYPT] -> [stock decompression] -> [listener] > > It looks like the standard encryption algorithms may have been broken > (see > <http://www.nytimes.com/2007/04/29/technology/29cnd-encrypt.html? > ex=1335499200&en=aa06d98a600afc6f&ei=5088&partner=rssnyt&emc=rss>), > so I'm hoping to develop a good alternative. > > One of my research interests is encryption, and cell phones clearly > need some help. Will hacking along these lines be possible in the > upcoming release? The chip sets used in the phone might not expose > enough to do this, and if it's not possible, I'd like to know early! > > Best Regards, > Patrick _______________________________________________ OpenMoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community