carcarx wrote:
> On Feb 29, 9:12 am, John Navas <spamfilt...@navasgroup.com> wrote:
>> CDMA has also been cracked. (I posted citations long ago.)
>
> Strange. I asked you specifically for them, but there was never a
> response.
> Please retrieve them and post them again.
Navas must have gotten his information from this...
But first...consider the source, Steve "Black Helicopter" Gibson
From
http://www.grc.com/sn/SN-130.txt
[quoting the relevant part]
STEVE: Both types of cellular technology, both GSM and CDMA,
unfortunately use encryption that was - I mean, I can just hear our
listeners getting ready for this - was designed by engineers and not by
crypto people.
LEO: Just like WEP.
STEVE: In their defense, in defense of the cell technology, back when
this was first done, it was much more expensive to have processing power
than it is now. At least in the case of GSM, it's based on a shift
register, I think it's three different shift registers with multiple
taps, which is one way of generating pseudorandom data. They've tried,
the people doing it tried to keep this as a trade secret, tried to keep
it proprietary. Bottom line is it's been cracked.
LEO: Now, you understand first of all this isn't - this is CDMA. And
it's EVDO, it's EVDO. It's Sprint.
STEVE: Right. Right. Now, exactly. Now, but CDMA has been cracked
also. So...
LEO: And I don't know if EVDO really uses CDMA technology. It's on
those frequencies, but it might use something else.
STEVE: Actually it does. All EVDO is really doing is aggregating a
bunch of channels together. And essentially that's where you get all
this extra bandwidth...
LEO: Oh, interesting.
STEVE: ...is it just pulls a bunch of cell channels together and uses
them all in parallel in order to increase its speed.
LEO: How interesting.
STEVE: I don't know one way or another for sure whether there's an
additional layer of encryption on top of the standard cell technology.
And when I - again, as I started saying, I don't want to freak out our
listeners. It's not like, you know, CDMA and GSM has been cracked to
the degree, for example, that WiFi has been. But there are papers on
the 'Net that talk about how this stuff can be cracked. So it's not
like there's super-strong, industrial-grade, current state-of-the-art
crypto. The problem is, these technologies, these digital cellular
technologies are so old, and now so widely deployed, that they can't be
updated without obsoleting the entire network. And they're, I mean,
they're encrypted to the extent that you have to really, really, really
want to crack them in order to get inside them. But it is possible.
Has been done.
LEO: I'm reading here that EVDO uses a 42-bit pseudo-noise sequence
called a "long code" to scramble the transmissions.
STEVE: Right. I mean, and...
LEO: That's not very long.
STEVE: No, it's not. And again, it's...
LEO: And then it uses AES.
STEVE: On top of it.
LEO: Yeah. Well, wait a minute.
STEVE: Okay.
LEO: Now, wait a minute. The long code scrambles transmissions through
the standardized cellular authentication and voice-encryption algorithm,
which is probably the one that's broken, to generate a 128-bit sub-key
called Shared Secret Data, SSD. This key feeds into an AES algorithm to
encrypt transmissions.
STEVE: Well, that does sound pretty good.
LEO: If it's using AES with a 128-bit key generated by random, by
pseudo-noise...
STEVE: Yeah, it doesn't sound like it's using any kind of a public key
technology. And I don't know where the shared secret comes from. It
might be based on the phone number, or maybe it's established ahead of
time? Anyway, it is on my list of things to research deeply. So I can,
you know, we'll spend an hour here before too long talking in detail
about cellular encryption technology because I know lots of people are a
little anxious about it.
LEO: Well, the thing that makes me anxious is maybe EVDO is secure, the
data's secure. But it sounds like voice transmissions over GSM and CDMA
are not.
STEVE: Right. They would be relying on that initial level of
obfuscation, which you really cannot consider as being encryption.
LEO: Right. You know, it's funny because, when we went from analog to
digital cell phones, I remember, as we talked about earlier, analog cell
phones, just like analog land lines, were completely, completely
monitorable. And I remember asking hackers; and they said, well, we
don't know how, but probably you could hack into it.
STEVE: Probably.