cellphones as room bugs

[Ian Farquhar (ifarquha)]

The other problem for this technique is battery life.

Let's assume we can shove a firmware update/hack/whatever into the phone to enable snooping, it's still transmitting when acting
as a bug.  Even if this feature is only enabled when the phone is geolocated somewhere "interesting", the reduction in battery
life is going to be significant.  If your phone has a standby time of days, and you're used to shoving it on the charger rarely,
then suddenly you're doing it several times a day, you're going to notice.  Even if you are the dumb, stupid criminal the
government likes to tell us that surveillance always catches.

I suppose that it could be argued that you could use silence detection etc. to reduce power used, but most phones are pretty
aggressive at power saving already.  I doubt there are huge savings to be made which haven't been implemented already.

Ian.

-----Original Message-----
From: owner-cryptography at metzdowd.com [mailto:owner-cryptography at metzdowd.com] On Behalf Of Taral
Sent: Monday, 4 December 2006 2:26 PM
To: tls at rek.tjls.com
Cc: John Ioannidis; cryptography at metzdowd.com
Subject: Re: cellphones as room bugs

On 12/3/06, Thor Lancelot Simon <tls at rek.tjls.com> wrote:
> It's been a while since I built ISDN equipment but I do not think this 
> is correct: can you show me how, exactly, one uses Q.931 to instruct 
> the other endpoint to go off-hook?

That's the same question I have. I don't remember seeing anything in the GSM standard that would allow this either.

--
Taral <taralx at gmail.com>
"You can't prove anything."
    -- Gödel's Incompetence Theorem

---------------------------------------------------------------------
The Cryptography Mailing List
Unsubscribe by sending "unsubscribe cryptography" to majordomo at metzdowd.com

---------------------------------------------------------------------
The Cryptography Mailing List
Unsubscribe by sending "unsubscribe cryptography" to majordomo at metzdowd.com