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Researchers can slip an undetectable trojan into Intel’s Ivy Bridge CPUS
- foldor 13y agoThis is interesting, but I wonder what the real world application of this change would be. According to Linus, the Intel RdRand is only used as one of many sources of entropy in /dev/random. So even if it were compromised it wouldn't have a large impact on security. Source: http://www.change.org/en-GB/petitions/linus-torvalds-remove-rdrand-from-dev-random-4/responses/9066 http://www.change.org/en-GB/petitions/linus-torvalds-remove-...
- clarry 13y agoNot all applications use Linux. Not all applications go through Linux's /dev/random for their random needs. If you look into the discussion on, say, Theodore Tso's G+ entry on rdrand, you'll find that some people are eager to skip the OS and use rdrand directly.
- chm 13y agoSomebody posted this link on another discussion: http://cm.bell-labs.com/who/ken/trust.html http://cm.bell-labs.com/who/ken/trust.html There's no way to know for sure, but I don't think this is a problem for the average consumer. I'd like to think serious black hats are not amateur fishermen who use a bait to catch anything that passes by. I picture them more like a sniper waiting for the perfect shot on a valuable target. In other words, yes every system could be compromised, but the ones that are will be the ones holding more valuable information. And those are few relative to the mass of average joes. But then one might get an advantage from controlling a botnet, and use it to attack more valuable targets. I don't really know :)
- sliverstorm 13y agoIt's the same as security always is. "What are my enemies capable of" is an absolutely critical component of the security equation that cannot be overlooked.
- MertsA 13y agoThe only caveat is that if RdRand was made to output the bits about to be sent out XORed with a stream of AES(n++, NSA_KEY) then you get seemingly random data that is 100% deterministic once you know the key and completely invisible if you don't know the key.
- chacham15 13y ago> In an e-mail, Paar stressed that no hardware trojans have ever been found circulating in the real world and that the techniques devised in the paper are mere proofs of concept. No need to get all worried about this type of hack. First of all, it is just an idea, not something actually found. Secondly, the hack would be all too easy to detect: run rdrand 2^31 + x times and see if x is a repeated sequence.
- chatman 13y agoIt is not "too easy to detect" a bad PRNG from a good one.
- deleted 13y ago[deleted]
- ambiate 13y agoI agree. Sounds like a number theory halting problem. Generate sequences of numbers continually, ad infinitum, and determine if distribution rates are (?). How would one begin to fill in that question mark? A PRNG that spits out three million 'zeros' and a single 'four' is as reliable as a PRNG that spits out an even distribution of random numbers.
- claudius 13y agoIsn’t the problem with detecting bad randomness that you can’t be sure about your decision? That is, if you accept a certain probability of falsely identifying a RNG as biased, I don’t see why this should be a fundamentally difficult problem, at the very least for the generator with four million 0s and a single 1: The probability that a good RNG spits out less than a thousand 1s in four million queries is negligible compared to the probability that it returns between 1.5 and 2.5 million 1s. Of course, it will be harder to detect more sophisticatedly broken generators, but still, without requiring certainty, it should be possible to make some sensible claims?
- Someone 13y ago
- ddalex 13y agoAlarmist title - you can't execute code undetected, as you would think from the title, you can alter the manufacturing process to poison the random number generator. The alteration is not detectable using current testing procedures. It's not any big deal, people already are treating the RDRAND instruction as poisoned.
- makomk 13y agoBefore: it's no big deal, how likely is is that someone could compromise RDRAND without anyone noticing After: what's the big fuss, everyone who counts already treats RDRAND as compromised Why does this always happen with stories like this one?
- denosa 13y agoPossibly because almost every single post like this brings out the same apologists. The same apologists get voted sky high. The proper question is how do the same apologists get voted to the moon and posts such as this get deleted? We already know of corporate astroturfing. Could that be happening on HN? Nah, unpossible.
- harshreality 13y agoAre you suggesting NSAstroturfing? The government has engaged in that sort of thing before. http://rezn8d.net/2012/10/19/us-defense-contractors-sock-puppet-scheme-busted-your-social-media-is-infected/ http://rezn8d.net/2012/10/19/us-defense-contractors-sock-pup...
- phazmatis 13y agoDoesn't sound undetectable to me. Isn't this what the die hard tests are for?
- Sae5waip 13y agoNo it's not. The die hard tests don't help against malice. Consider this PRNG: `"random"_bitstream` := AES('00000000...', NSA_KEY)
- tptacek 13y agoNo, researchers could theoretically slip a difficult-to-detect trojan into Ivy Bridge if they controlled the manufacturing process for the chip. The paper is extremely interesting and important, but this headline does it a grave disservice. There is actually nothing specific to Ivy Bridge about the technique; Ivy Bridge is simply a case study in the paper for how the technique might be valuable to an attacker.
- acqq 13y agoExactly, the mentioned researchers haven't done anything with any schematics of the real Intel processor. It's "what we believe we could do if we'd have the control of the production of a processor with the RND like the one described by Intel to exist in their CPU's starting with their Ivy Bridge architecture." Still, it's interesting to see how such things could be done.
- petermonsson 13y agoThe choice of BIST over scan/ATPG makes this attack theoretically possible on Ivy Bridge. If Intel had used scan/ATPG then this attack could not have worked even in theory. Unfortunately, I don't have the insight to understand why scan/ATPG could introduce a backdoor. Disclaimer: I don't think that this attack is even theoretically feasible given just a few real world constraints. I am just nitpicking
- archer174 13y agoScan chains by design, give you the ability to load each flop with whatever value you want. Then you can toggle the clock and see the result. If you were very resilient about this you may be able to gather information about the structure. Without a GDS or netlist this is all very far fetched and unlikely. I've said before, but it is far more likely to bribe a rogue designer than to introduce back doors at this level.
- tsaoutourpants 13y ago<3 the Trojan Horse from Burning Man 2011 :D
- lawnchair_larry 13y agoWorst headline ever. Ars is very bad at reporting on security issues.
- ffrryuu 13y agoNSA can do much better than that. US tech can no longer be trusted.