[eb@comsec.com: Re: Maybe It's Snake Oil All the Way Down]
- Forwarded message from Eric Blossom <[EMAIL PROTECTED]> - Date: Tue, 3 Jun 2003 13:25:50 -0700 From: Eric Blossom <[EMAIL PROTECTED]> To: [EMAIL PROTECTED] X-Orig-To: John Kelsey <[EMAIL PROTECTED]> Cc: [EMAIL PROTECTED], EKR <[EMAIL PROTECTED]>, Scott Guthery <[EMAIL PROTECTED]>, Rich Salz <[EMAIL PROTECTED]>, Bill Stewart <[EMAIL PROTECTED]>, cypherpunks <[EMAIL PROTECTED]>, [EMAIL PROTECTED] Subject: Re: Maybe It's Snake Oil All the Way Down In-Reply-To: <[EMAIL PROTECTED]> User-Agent: Mutt/1.4i On Tue, Jun 03, 2003 at 10:42:01AM -0400, John Kelsey wrote: > At 10:09 AM 6/2/03 -0400, Ian Grigg wrote: > ... > > (One doesn't hear much about > >crypto phones these days. Was this really a need?) Yes, I believe there is a need. In my view, there are two factors in the way of wide spread adoption: cost and ease of use. Having spent many years messing with these things, I've come to the conclusion that what I personally want is a cell phone that implements good end-to-end crypto. This way, I've always got my secure communication device with me, there's no "bag on the side", and it can be made almost completely transparent. > And for cellphones, I keep thinking we need a way to sell a secure > cellphone service that doesn't involve trying to make huge changes to the > infrastructure, ... Agreed. Given a suitably powerful enough Java or whatever equipped cell phone / pda and an API that provides access to a data pipe and the speaker and mic, you can do this without any cooperation from the folks in the middle. I think that this platform will be common within a couple of years. The Xscale / StrongARM platform certainly has enough mips to handle both the vocoding and the crypto. Also on the horizon are advances in software radio that will enable the creation of ad hoc self organizing networks with no centralized control. There is a diverse collection of people supporting this revolution in wireless communications. They range from technologists, to economists, lawyers, and policy wonks. For background on spectrum policy issues see http://www.reed.com/openspectrum, http://cyberlaw.stanford.edu/spectrum or http://www.law.nyu.edu/benklery Free software for building software radios can be found at the GNU Radio web site http://www.gnu.org/software/gnuradio Eric - End forwarded message -
[eb@comsec.com: Re: Maybe It's Snake Oil All the Way Down]
- Forwarded message from Eric Blossom <[EMAIL PROTECTED]> - Date: Tue, 3 Jun 2003 15:50:37 -0700 From: Eric Blossom <[EMAIL PROTECTED]> To: [EMAIL PROTECTED] X-Orig-To: John Kelsey <[EMAIL PROTECTED]> Cc: [EMAIL PROTECTED], EKR <[EMAIL PROTECTED]>, Scott Guthery <[EMAIL PROTECTED]>, Rich Salz <[EMAIL PROTECTED]>, Bill Stewart <[EMAIL PROTECTED]>, cypherpunks <[EMAIL PROTECTED]>, [EMAIL PROTECTED] Subject: Re: Maybe It's Snake Oil All the Way Down In-Reply-To: <[EMAIL PROTECTED]> User-Agent: Mutt/1.4i On Tue, Jun 03, 2003 at 06:17:12PM -0400, John Kelsey wrote: > At 01:25 PM 6/3/03 -0700, Eric Blossom wrote: > ... > I agree end-to-end encryption is worthwhile if it's available, but even > when someone's calling my cellphone from a normal landline phone, I'd like > it if at least the over-the-air part of the call was encrypted. That's a > much bigger vulnerability than someone tapping the call at the base station > or at the phone company. GSM and CDMA phones come with the crypto enabled. The crypto's good enough to keep out your neighbor (unless he's one of us) but if you're that paranoid, you should opt for the end-to-end solution. The CDMA stuff (IS-95) is pretty broken: *linear* crypto function, takes 1 second worst case to gather data sufficient to solve 42 equations in 42 unknowns, but again, what's your threat model? Big brother and company are going to get you at the base station... At our house we've pretty much given up on wired phone lines. We use cell phones as our primary means of communication. Turns out that with the bundled roaming and long distance, it works out cheaper than what we used to pay for long distance service. There is that pesky location transponder problem though. > ...which will basically never be secured end-to-end if > this requires each of those people to buy a special new phone, or do some > tinkering with configuring secure phone software for their PDA. "Hmmm, > which key size do I need? Is 1024 bits long enough? Why do I have to move > the mouse around, again, anyway?" It doesn't have to be hard. No requirement for PKI. Just start with an unauthenticated 2k-bit Diffie-Hellman and be done with it. Eric - End forwarded message -
