Encryption/decryption - I have seen national and local TV reports that GSM and analog phones can be cloned and that the calls can be intercepted.
Eric is, to my knowledge, correct on this. GSM has been 'cracked', but only by getting a SIM card in the laboratory and trying many different combos and making some educated guesses based on what comes out the other end. It has never, again to my knowledge, been cracked over the air (neither for cloning nor for eavesdropping). The anti-eavesdropping is accomplished by encryption but I have never seen any data on what methods they use (for obvious reasons) so it is hard to say how secure it really is.
As for CDMA, again I have to admit some ignorance about whether they use encryption (to my knowledge they do not - more on that later), but I can say that the CDMA in and of itself is not what makes the link secure. The spreading codes that are used are public knowledge and each of the handsets uses the same spreading code, but offset in time (hence the 4.4 trillion handset codes, which is really a measure of the time it takes for the code to repeat (2^42)).
So, why is CDMAOne secure? First, it is more complicated than GSM, or especially analog. It is hard to build a scanner out of off-the-shelf parts even if CDMAOne is completely unencrypted. But it is not impossible - as I've said before I suspect that if three or four of the people on this board got together we could build a crude scanner out a really high powered DSP and some other parts (e.g. a codec). But what I do not know is whether CDMAOne uses encryption like GSM does. It is a good bet that they do, but I have never seen reference to it. Anyone know?
Clark |
