End-to-end encrypting US GSM phones?

[Ryan Lackey]

Quoting Trei, Peter <ptrei at rsasecurity.com>:

> I don't quite understand why getting encrypted VoIP working on a Palm Pilot
> (16-33 MHz dragonball) is the 'Holy Grail'. I would have said that the HG is
> an affordable, working, portable and pocketable encrypted VoIP system with
> free software, regardless of platform. The Ipaq is 2-300$ more than a Palm 
> device, but is that the whole issue? Ipaqs have much better cpu power 
> and memory, and decent Linux ports. Go for the low-hanging fruit first.

"Everyone" has palm pilots already.  WinCE-based PocketPCs haven't
made much of a dent in the marketplace.  There is also a very large
developer community for palm apps, and they're widely deployed in 
corporations.

If you're assuming users will buy a dedicated device *and* put linux
on it, that's reasonable (or sell pre-packaged systems).  Otherwise,
you also need to develop for WinCE on the PocketPC.

I still would like to see from someone who is good at integer voice
encoding whether a 33MHz dragonball can do tolerable-quality voice at
14.4kbps; I'm sure it's good enough to distinguish "ki" from
"eight-ball", but I'd like something good enough to distinguish
"weight, y'all" from "eight-ball"

Since it's very unlikely any pda will have full duplex audio anytime
soon, I think the bluetooth headset is the only viable solution; I'm
going to get one for my t39m soon enough, and then I'll experiment
with linux bluetooth support and try to get bluetooth audio integrated
into OSS on my laptop, as a proof of concept.  That done, it's just a
question of running linux on an ipaq for a simple demo, with libgsm
compiled as integer; then maybe something more efficient.  I'm pretty
sure someone has made the bluetooth headset work with linux already,
so it's just a question of kernel patches.

The security of this would depend somewhat on the bluetooth
encryption, although I'd be happier trusting unencrypted but
low-propagation bluetooth vs. a PSTN/cell link.

-- 
Ryan Lackey [RL7618 RL5931-RIPE]	ryan at havenco.com
CTO and Co-founder, HavenCo Ltd.	+44 7970 633 277 
the free world just milliseconds away	http://www.havenco.com/
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