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Cell Phone Encryption Exploit Demonstrated
Saxophonist brings us a story from Forbes about security researchers who demonstrated a new method for breaking the encryption on GSM cellular signals. The presentation was made at the recent Black Hat conference, and it's notable for the fact that the technique only requires "about half an hour with just $1,000 in computer storage and processing equipment." The researchers also claim to have found a faster method, which they intend to market for $200,000 - $500,000. Quoting:
"Undetectable, 'passive' systems like the one that Muller and Hulton have created aren't new either, though previous technologies required about a million dollars worth of hardware and used a "brute force" tactic that tried 33 million times as many passwords to decrypt a cell signal. All of that means, Hulton and Muller argue, that their cheaper technique is simply drawing needed attention to a problem that mobile carriers have long ignored--one that well-financed eavesdroppers may have been exploiting for years. 'If governments or other people with millions of dollars can listen to your conversations right now, why shouldn't your next-door neighbor?' Muller says."
Unless their patent application is kept confidential by the government for reasons of national security, it will be published within 18 months. You'll be able to learn how the trick works from it (if you're an expert in the field and you cannot make it work, no patent should be granted). You're not allowed to exploit that commercially, of course, but at least you can have fun and pull a few pranks with it. You could claim you're psychic.
I'm wondering how you ever could tune in to the correct conversation, with thousands of mobile phones transmitting at the same time.
Bert
How is it that it caught on for the web (credit card payments over SSL), but still barely for personal communications (gpg, encrypted IM)?
That's a very good question.
One idea I've heard is that when SSL was first developed, the web was in its infancy and nobody really felt happy about the idea of sending their credit card details over it. The fact that it was relatively easy to eavesdrop on a computer network was fairly well known. This was no good to anyone who wanted to do business (OK, porn sites) over the web, and so SSL solved that problem by providing reassurance that nobody was eavesdropping.
The telephone system, on the other hand - that's been around so long that it's familiar technology and relatively few people are aware of how insecure it is. If you think GSM is bad (it's actually not that poor, and 3G introduces AES encryption), consider your land line. No encryption whatsoever and an analogue signal (so no computer equipment or specialised unusual codecs required to tap) between you and the telephone exchange.