Stealing Smartphone Crypto Keys Using Radio Waves 37
coondoggie writes "Encryption keys on smartphones can be stolen via a technique using radio waves, says one of the world's foremost crypto experts, Paul Kocher, whose firm Cryptography Research will demonstrate the hacking stunt with several types of smartphones at the upcoming RSA Conference in San Francisco next month."
Gives me hope.. (Score:1)
Breaking crypto with all these newer and newer tricks. So long as it's within the realm of possibility that my TPM can be broken, fear of DRM hath no hold on me.
Re: (Score:1)
Re: (Score:3)
Re: (Score:2)
This is why you password protect your keys.
Re: (Score:2)
Re: (Score:2)
Re:Van Eck side channel (Score:4, Informative)
This is not a new attack. It's been known for decades - this is the attack the NSA codenamed HIJACK, I believe (or it may possibly be NONSTOP, I always get the two confused). I know GCHQ's CESG were aware of it too.
Putting a radio transmitter next to something which may produce key-dependent interference (depending on, say, whether it's squaring (1) or multiplying (0) each bit of an RSA key) will yield a measurable interference pattern which leaks information about the keys.
Countermeasures are surprisingly similar to acoustic emissions attacks and timing attacks: blinding; routines/hardware circuits which don't exhibit key-dependent behaviour; better shielding, particularly of the ground and Vcc planes for the TX circuit.
Works for keyboards, too.
Clever. I like it. (Score:5, Informative)
So the CPU doesn't have a strong enough EM signal (note that all electronic processing generates EM waves) to send out the key processing details over any reasonable distance (tiny starting signal plus 1/r^2) . But it is a smartphone, and the CPU EM signal is strong enough to interfere with the (very!) nearby phone transmitter. And by examining that signal, you can tempest monitor the CPU from a much greater distance. Cool. The smartphone in effect has its own built in CPU EM signal amplifier.
The hard bit is the details. You need the right equipment, and the right algorithms to extract the signal and then reconstruct the key.
Re: (Score:2)
Actually TEMPEST.
Re: (Score:2)
further reading http://www.cl.cam.ac.uk/~mgk25/ih98-tempest.pdf [cam.ac.uk]
New Phone Case. (Score:5, Funny)
Great. Now I need a tin foil case for my phone too.
Electromagnetic Where Exactly? (Score:5, Interesting)
The radio-based device will pick up electromagnetic waves occurring when the crypto libraries inside the smartphone are used,
, but I can't see how it could actually be detecting anything inside the smartphone as the waves emitted by the little electrons zipping around are hardly going to be detected, not to mention identifying those particular disturbances amongst everything else would be impossible. Is it actually detecting the stuff as the cellphone transmits/receives if then? I'm far from an expert in this, so any explanation would be great.
Re:Electromagnetic Where Exactly? (Score:4, Informative)
It's a pretty typical side-channel attack. It's detecting the RFI emitted during computation, and using that to determine the key. So, yes, it's detecting the waves emitted by the little electrons zipping around inside the smartphone.
Re: (Score:2)
I'll believe it when I see it. Even then, I'll only believe it when I see it working outside a perfectly shielded Faraday cage, more than once.
Re: (Score:2)
This, of course, is not quite
Re: (Score:2)
Oh, I'm painfully aware that computer equipment throws off all sorts of hash, well up into the hundreds of MHz range. I can hear my ADSL modem a good quarter of a mile away on 145.6875MHz - in the house its emissions are strong enough to blot out the local repeater.
I don't believe it's possible to recover the encryption key by listening to these pulses. There's so much else going on, and it's not like each little wave is labelled "this is part of the encryption key".
Re: (Score:2)
I don't believe it's possible to recover the encryption key by listening to these pulses. There's so much else going on, and it's not like each little wave is labelled "this is part of the encryption key".
No, but you can set things up so that if a particular key bit is a "1," the system will work harder than if it is a "0" by selecting particular plaintext or ciphertext to be encrypted or decrypted. It may be a small difference buried in noise, but if you repeat the experiment enough times it will become detectable. Worse still, it may be the case that you do not have to choose the plaintext/ciphertext at all, but simply know what is being encrypted/decrypted: maybe you can intercept the ciphertext, or
Re: (Score:1)
Re: (Score:1)
Dude, they're using RADIO WAVES! That shit's like magic. It's a freakin' INVISIBLE LIGHT ELEMENTAL. No one understands how that stuff works. There is no defense from it.
Scariest thing I've ever read. Totally ruined my "Data Privacy Day" party.
Actually, this is well known... (Score:3)
Re: (Score:2)
On Android you could write an app that runs in the background and randomly interrupts the foreground app or does useless bits of crypto while it is active to foil these attacks.
Re:Electromagnetic Where Exactly? (Score:5, Interesting)
No, actually it IS radio waves from the little electrons zipping around in the phone being detected. Of course, little electrons zipping around are always involved in radio waves.
You'd be amazed what signal processing can do, especially if you can also see in a video when the function your looking for was triggered.
This is another example of Van Eck phreaking [wikipedia.org]. It's so easy in some cases, it can be accidental. Back in the early '80s, I noticed the interference on channel 5 of the TV had a repeating pattern to it. As I studied it carefully, I realized it was the screensaver from my PC in the next room.
Mod parent down (Score:5, Interesting)
TEMPEST (Score:1)
Re: (Score:1)
That's the hard way of dealing with this problem. The real reason CRI is showing this is to sell their patented solution that statistically decorrelates the side channel info being transmitted, thereby rendering such emissions meaningless. They did something similar with differential power analysis on ISO7816 smart cards, especially the clockless asynchronous logic used by N X P smart cards.
load of crap (Score:1)
My phone has a dual core 1.2ghz cpu. Your telling me that its possible to decode the signals flowing through the phones circuits remotely ? whats the energy level of the RF radiating from the phone, NOT including the WIFI / bluetooth / LTE cdma / spurious LCD emissions ? assuming you did shut these off, you would need to stick the thing in a RF shielded room with a yagi up the phones behind to get enough signal strength to decode electrical impulses operating at 1.2GHZ!
Re: (Score:1)