At 7:38 PM 04/21/94 -0400, Perry E. Metzger wrote:
Peter Wayner says:
How hard is it to reprogram the DSP that comes with a cellular phone right now? I've never opened one up. Can you just unsolder a rom, read it, insert your own code for DH key exchange, add some encryption, burn a new ROM and have a secure phone?
You would also have to open up the base station for the cell, unsolder its roms, read them, insert your own code for DH key exchange, add some encryption, and put it back, and I suspect that the cellular vendor would get mad at you.
Perry
Aha. here is where you can enlist the hacker community's experience. Various phreaker types have been reprogramming thier cellulars for quite a while- usually to do free calls instead of encrypted calls, but the same ideas apply. I don't know if anyone has done anything with the DSPs, but there are various files floating around with the codes to break into debug-mode and such for a while. Check yer local underground BBS...