Cell Phone Encryption?

Black Diamond asks: "I know I'm not up to speed on cell phone encryption, but I was wondering, are there any cell phones that let you handle the encryption from your end of things? Something along the lines of a phone you hook up to your computer to input specific encryption keys for specific contacts, as well as a private key for yourself. Is such a thing plausible, or should you trust the standard encryption that comes on some cell phones nowadays?"

Comments

Similar to PGPfone...

[Chasing Amy]

This isn't exactly what you're asking about, but the closest thing I can think of offhand would be PGPfone--a product abandoned years ago for encrypting voice communications much as PGP encrypts text.

There are both binaries and source code available here: http://www.pgpi.org/products/pgpfone/

Windows and Mac only, and it's a very crude app... It would be nice for someone to develop something more robust and with better features.

Re:Some thoughts from a ham

[nbvb]

Correct, CDMA is spread-spectrum and the encryption is relatively difficult to crack.

Nobody's been able to demonstrate real-time listening capabilities (yet).

But it is a well-known fact that the law enforcement guys have taps at the cellular switches, so they just plug into the call before it goes to hardwire -- they don't even bother trying to listen out of the air, and why should they? It's a lot easier to listen at the switch .........

Now, as for GSM, its encryption is definitely crackable in realtime... In fact, there have been industrial espionage problems across the English channel because of this .... go look it up :)

Re:GSM phones encrypt anyway - NOT

[wowbagger]

It is trivial for anybody with the resources to build a faster than light drive, too - for some definitions of "with the resources".

It would depend upon whom this guy wishes to protect his conversations against - J. Random Carbonunit or Special Agent TLA.

If the former, than the encryption used in GSM is enough - few people have the gear to modulate and demodulate a GSM signal with proper time slotting, time of flight correction, etc. Making a GSM signal is HARD - I build gear that does it.

If the latter, then they won't screw around picking the signal off the air - they will throw a CALEA intercept on his phone when it hits the PTSN. Then the only thing that can protect him would be VERY strong encryption seperate from the phone - which as I said in my first posting is difficult due to the nature of digital phones.

Lastly, if he is trying to protect himself from Special Agent TLA, encrypting his signal like this won't help - it will just raise a big red flag saying "Look At Me! I Am Hiding SomeThing!". He would be far better served making an innocuous word code and using that.

It is possible, and it is real

[kousik]

But not in the form you say. There exist chips which will do a Diffie-Hellman exchange to set up a secret key, and then do AES encryption on the whole conversation. Comes as a Sony-Ericsson accessory.

Of course, lack of standard make these chips non-interoperable (not encryption/decryption but key management). Once it becomes popular standards need to emerge.

Motorola

[kruczkowski]

I know that Motorola just released an addon to a off-the-slef phone that adds comsec.

From what I understand, phones with this devices are aproved by NSA for secret transmittions.

Doing a google seach I came up with this:

http://www.cellular.co.za/phones/generaldynamics /g eneral_dynamics_sectera_secure.htm