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Researchers Find Way To Zap RSA Algorithm
alphadogg writes "Three University of Michigan computer scientists say they have found a way to exploit a weakness in RSA security technology used to protect everything from media players to smartphones and e-commerce servers. RSA authentication is susceptible, they say, to changes in the voltage supply to a private key holder. While guessing the 1,000-plus digits of binary code in a private key would take unfathomable hours, the researchers say that by varying electric current to a secured computer using an inexpensive purpose-built device they were able to stress out the computer and figure out the 1,024-bit private key in about 100 hours – all without leaving a trace. The researchers in their paper outline how they made the attack (PDF) on a SPARC system running Linux."
...whether interrogating a human or a computer, apparently it is a simple matter of voltage.
Probably much more threatening(though, frankly, that pleases me) to DRMed embedded systems and similar gear that is supposed to be "secure" vs. its immediate environment; but is also in the hands of the public in huge quantities.
Yeah, if I can break into your datacenter and clamp some crazy widget onto the (presumably multiple) lines supplying your server's PSUs, a clever voltage attack is not the biggest of your problems.
If, on the other hand, you can guess the private crypto keys out of a DRMed PMP just by clipping a 15 dollar device from some shady mod-chip vendor to the recharging port and waiting a few days, heads will roll. There are a lot of devices these days that are designed to keep keys secret from the owners of the hardware. Particularly for common ones, voltage attack devices might well become fairly common advanced hobbyist and/or grey market items...
If someone has physical access to your machine, then you have already lost.
Im a gamer, not a grammer major. This post is full of spelling and grammer mistakes.
Depends on what the DRM is trying to protect. Music players, video players for downloadable content, and basically anything where the content isn't tied to a physical object like a game disc will need a private key of some kind to encrypt the data on their volatile storage. While most of this will probably be done using symmetric encryption, you still need some way for the server that hands out the content to prove that it is a real device and not an emulated device, and that's normally done with a locally stored private key.
...electronic torture?
Wattage-boarding
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"the researchers say that by varying electric current to a secured computer"...
Um, if they have physical access to the computer (in order to monkey with the power), why would it be considered secure?
The faults described by the paper are so ... what's the word ... specialized that it challenges believability. Not only does the attacker have to have physical access -- and likely pretty good physical access -- they have to know precisely when the encryption algorithms are being performed so that the faults can be induced then and only then otherwise the operation of the computer will be compromised. Furthermore, the faults must be induced at a reasonable, but not too great, rate, and at randomly varying times in the computation, so as to explore the full error space and have insight into the keys. And the computations have to be repeated MANY times over in order to extract enough information. So, not only do attackers have to know exactly, to the microsecond, when the system under attack is computing the RSA algorithm, they also have to be able to vary the voltage to the CPU. Their physical proof of concept, as much as it is described in the paper, is contrived. Their assertion that the technique does not require physical access is wholly unsupported. Color me skeptical. Anyone with this level of access is going to be able to do more than trigger faults.
The paper asserts that the probes can be done without leaving any trace. I don't know about the authors, but the voltages on my computers are monitored by software and excursions logged so that I can know if/when there are problems. Since the RSA-breaking technique requires substantial exploration of the response to voltage tweaks, it is likely to be detected by a decent monitoring program.
Finally, the PDF does not carry any publication information suggesting strongly that it describes work that is not peer-reviewed. It is shoddy science to bypass peer review and release to the general public.
Put my fist through my alarm clock with its ding-dong death inside my ear. - The Blackjacks.