301–310 of 395 posts
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People who intend to enter a middle school and kill kids can hide their plans and communications using 256-bit encryption. Edit: Devil's advocate.
Or they could be loners or they could meet and communicate face to face.
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Spying on your own citizens codenamed as civil war. How nice. Nowhere in the article does it state that these methods can be used against US persons separate from other protections against surveillance on US persons, nor does it give the impression that this is special to US persons: The agency’s success in defeating many of the privacy protections offered by encryption does not change the rules that prohibit the del…
You must have been living under a rock for the past few months. Welcome to September, where we now know that to not be the case.
Welcome to September, where the NSA can keep any data it accidentally collected about US persons for five years if its plaintext. And if that data is encrypted, it can keep data on US persons forever.
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> I have no problem with the NSA being able to break encryption, that's in fact part of their job. Their "breaking" of encryption is a combination of purposefully introducing vulnerabilities into standards, surreptitiously altering software and hardware to give the NSA a backdoor, hacking into private systems and stealing keys, etc etc. I'm cool with an NSA super computer trying to brute force my VPN traffic to YouTu…
I will bet good money that the NSA has never bothered to try and plant backdoors in encryption standards. If the NSA recommends AES to the US government, but knows there's a vulnerability, then they have to assume that any adversary may be as good as whoever designed it. Which means an adversary would be perfectly capable of discovering and exploiting the weakness. Which in turn means the NSA has just made the entire…
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The best publicly known attacks on RSA reduce the attack time by a few orders of magnitude at best. A functional quantum CPU could reduce that by a few more orders. Your 4096-bit RSA key is still 2^3072 times harder to break, so even with reductions we're still talking about "heat death of the universe" amounts of time to brute force. RSA has issues but as of yet hasn't yielded entirely to cryptanalysis. As the artic…
"Your 4096-bit RSA key is still 2^3072 times harder to break," No, because the difficulty of breaking RSA keys doesn't scale in the same way as symmetric encryption. Integer factorisation is much easier than a brute force search of the keyspace. A 1024-bit RSA key is believed to be roughly equivalent to an 80-bit symmetric key. A 3072 bit key is about as hard to brute force as an 128-bit symmetric key. (Source: http:…
In any case, you can choose a public key exponent large enough to still make it a hard problem to crack in a reasonable amount of time. Barring some huge vulnerability in RSA that hasn't been discovered in 30 years of public scrutiny, of course.
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> Quantom computing cannot break all of crypto. Correct (except for the spelling of "Quantum"). > Anything based on P!=NP is believed to be secure against quantom computing, and there are several encryption methods backed by P!=NP Incorrect, well mostly. The deal is that there are problems that can be done in "polynomial time" (how long it takes is not exponential in the size of they key) for a normal computer (or pe…
> the ones that CANNOT be done on polynomial time is "NP". I see you've solved one of the great open problems! NP is defined as problems that a nondeterministic turing machine can solve in polynomial time. Imagine, if you will, a turing machine that when it "branches" always chooses the right path (Or: chooses "both" without overhead)
> Fortunately, there are problems which are NOT in BQP
We don't know yet if NP \ BQP is non-empty (and neither do we know if BQP \ NP is non-empty).
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> the ones that CANNOT be done on polynomial time is "NP". I see you've solved one of the great open problems! NP is defined as problems that a nondeterministic turing machine can solve in polynomial time. Imagine, if you will, a turing machine that when it "branches" always chooses the right path (Or: chooses "both" without overhead)
The latter of which sounds suspiciously like what a quantum computer does. How sure are we that BQP != NP?
However a quantum machine that would be capable of post-selection is described by the more powerful class PostBQP = PP, and we know that PP includes NP, so this justifies your analogy.
I don't know much about quantum physics or quantum computing, so I may be mistaken, but it seems to me that post-selection is more of a philosophical construct than something that is physically possible, though.
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> the ones that CANNOT be done on polynomial time is "NP". I see you've solved one of the great open problems! NP is defined as problems that a nondeterministic turing machine can solve in polynomial time. Imagine, if you will, a turing machine that when it "branches" always chooses the right path (Or: chooses "both" without overhead)
The latter of which sounds suspiciously like what a quantum computer does. How sure are we that BQP != NP?
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Are you sure about that? As far as I understand it, generic quantum computation would cut that '3072' in half , and using quantum computers specifically for factoring reduces problems to a low polynomial time.
Correct. Shor's algorithm renders any use of RSA... pointless. And while there are limits to the applicability of Grover's algorithm, you're correct that it effectively cuts the number of bits in any cryptosystem it applies to in half. Which, to my nonexpert eyes, looks to be most of them.
Shor's algorithm is very tasty, but when the real world demonstrations at top research facilities are saying, "yes, we factored 21 into 7x3, but WITH ENTANGLEMENT"[1] it makes me think that scaling to RSA-size prime factors is still a good way off.
Listen, the US government is powerful, but building a full scale quantum crypto decoder ring in complete secrecy _decades_ ahead of everyone else? I just don't think so. Maybe I'm a sheep for not wanting to believe the government so powerful and corrupt, but the whole thing sounds like a tin foil fantasy.
I don't doubt they would if they could, though. And they've done as much as they can with present day tech: supercomputers, mass data collection, penetration of target systems, exploiting SSL's many weaknesses, tapping undersea lines, and legally strong-arming perceived threats into giving up their encryption keys. I just don't think we need to get science fiction involved.
[1] http://www.nature.com/nphoton/journal/vaop/ncurrent/full/nph...
There really should be no doubt at all that there is corporate espionage and insider trading going on. On one hand, if the NSA approached this with giving helpful 'heads up' when a US-based multinational's overseas factory might be planning to strike, or provide their foreign competitors' private dealings etc etc, they could win brownie points.
But you know it won't stop with screwing around with overseas business. If they are not already, you can bet that internal insider information is going to be traded and sold. You can't trust a rogue, so as long as it is not dismantled they are indirectly if not directly a hostile threat to your ability to conduct business.
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Android Browser on Google TV, and Java libraries hitting our APIs. Google TV and Android browsers are critical to our business.
I have written lots of Java code accessing HTTPS sites with 2048 or 3072-bit RSA. This is perfectly supported. You do not even need the Unlimited Strength Jurisdiction Policy Files to use such RSA key sizes (other algorithms are restricted). I can't comment on Android Browser on Google TV, but I very highly doubt it fails to support 2048-bit RSA keys. If that was the case, half the HTTPS websites would be unbrowsable…