This is merely a historical archive of years 2008-2021, before the migration to mailman3.
A maintained and still updated list archive can be found at https://lists.osmocom.org/hyperkitty/list/baseband-devel@lists.osmocom.org/.
Frank Rosengart frank at rosengart.deYou may have a look at http://www.cryptophone.de/en/background/cryptophone-technology/ They have gone through all the ideas coming up here, but a few years ago. I there would be any way to use the GSM voice channel for encrypted, reliable communication, they would have used it. Frank