Linked by David Adams on Wed 17th Aug 2011 17:53 UTC, submitted by HAL2001
Privacy, Security, Encryption Researchers have found a weakness in the AES algorithm. They managed to come up with a clever new attack that can recover the secret key four times easier than anticipated by experts. In the last decade, many researchers have tested the security of the AES algorithm, but no flaws were found so far. The new attack applies to all versions of AES even if it used with a single key. The attack shows that finding the key of AES is four times easier than previously believed; in other words, AES-128 is more like AES-126.
Thread beginning with comment 485641
To view parent comment, click here.
To read all comments associated with this story, please click here.
RE[4]: AES-254
by galvanash on Wed 17th Aug 2011 22:58 UTC in reply to "RE[3]: AES-254"
galvanash
Member since:
2006-01-25

Ok, impossible might not be the right word. But "exceedingly unlikely" doesn't do it justice either...

This is a little tidbit from a paper I read a while back (its a pdf - don't know where I got it from so I can't link to it)...


If you assume:

Every person on the planet owns 10 computers.

There are 7 billion people on the planet.

Each of these computers can test 1 billion key
combinations per second.

On average, you can crack the key after testing
50 percent of the possibilities.

THEN

The earth’s population can crack one
encryption key in 77,000,000,
000,000,000,000,000,000 years.


That is a bit more than "exceedingly unlikely" ;)

Reply Parent Score: 3

RE[5]: AES-254
by Drumhellar on Wed 17th Aug 2011 23:26 in reply to "RE[4]: AES-254"
Drumhellar Member since:
2005-07-12

I don't think there are words that could convey the unlikelihood of such an event and still be accurate.

To my ears, nearly impossible has always sounded more likely than exceedingly unlikely.

Either way, impossible is demonstrably wrong.

Reply Parent Score: 2

RE[6]: AES-254
by Morgan on Thu 18th Aug 2011 00:00 in reply to "RE[5]: AES-254"
Morgan Member since:
2005-06-29

How about "impossible within the natural lifespan of all currently living humans and their great*10^18 offspring"? That's my take on it.

After all, I doubt any humans would be left alive 70 quadrillion years from now to care what the encrypted data was. Even if there were, the computer being used to crack it would likely disintegrate completely a few hundred million years into the process.

So, yeah, "impossible" is, for all intents and purposes, a practical description.


Edit: And yes, I know galvanash's white paper called for 77 septillion years, but I was attempting to stay within the lifespan of the universe, give or take an order of magnitude.

Edited 2011-08-18 00:04 UTC

Reply Parent Score: 2

RE[6]: AES-254
by rirmak on Fri 19th Aug 2011 18:02 in reply to "RE[5]: AES-254"
rirmak Member since:
2009-06-23

Either way, impossible is demonstrably wrong.


This must be the most autistic sample of pedantry I've encountered since early April.

Oh, and for your arguing style you also have a raspberry from me in ;) semantics, as "demonstrably" may be the lamest excuse for a technicality this month (infantile hypercorrection).

Reply Parent Score: 1

RE[5]: AES-254
by reez on Wed 17th Aug 2011 23:57 in reply to "RE[4]: AES-254"
reez Member since:
2006-06-28

You know there are those Bitcoin folks with buildings brimmed with graphics cards. ;)

Think about quantum physics. It is also possible to just walk through a wall or slip through the earth, which in fact mots of us are "trying" 24/7. I know, it is a lot more likely to find a key, but the problem is people's (meaning at least mine) usually have a problem comprehending how (un)likely an event is. Just think about lotteries. People play because there is a chance, even though most of them know it is very unlikely. Walking through a wall is even free, still you be called insane if you tried, while nobody does when you take part in a lottery.

Reply Parent Score: 2

RE[6]: AES-254
by galvanash on Thu 18th Aug 2011 01:23 in reply to "RE[5]: AES-254"
galvanash Member since:
2006-01-25

Walking through a wall is even free, still you be called insane if you tried, while nobody does when you take part in a lottery.


I call anyone who plays the lottery insane. The lottery is a tax on people who failed high school math. Unless you are someone who does something like this:

http://www.gazettenet.com/2011/08/02/lottery-scheme-appears-to-caus...

The media makes it sounds like this is criminal or something... It should be applauded imo - finding such a flaw in what is essentially a rigged system should earn the finder a hefty payday, not accusations of criminality. The state needs to hire better mathematicians if they want to keep their system effectively rigged...

Reply Parent Score: 2

RE[5]: AES-254
by Slambert666 on Thu 18th Aug 2011 10:35 in reply to "RE[4]: AES-254"
Slambert666 Member since:
2008-10-30

The assumption is that the computing power stays constant.
If computer speed doubles every 18 months then the problem can be solved in 0.01 seconds 300 years from now, given the same amount of processing power, relatively. This is not taking into account algorithmic improvements.

Just like today we find historic ciphers like the Caesar cipher laughably easy to crack, the future will find AES256 easy to crack.

Reply Parent Score: 1

RE[6]: AES-254
by Kebabbert on Thu 18th Aug 2011 10:45 in reply to "RE[5]: AES-254"
Kebabbert Member since:
2007-07-27

The assumption is that the computing power stays constant.
If computer speed doubles every 18 months then the problem can be solved in 0.01 seconds 300 years from now, given the same amount of processing power, relatively. This is not taking into account algorithmic improvements.

Just like today we find historic ciphers like the Caesar cipher laughably easy to crack, the future will find AES256 easy to crack.

Not necessarily. Say that you need to try more combinations than there are atoms on earth to find a solution - do you really think that future will find it easy?

If you have 2^64 coins, then the pile would reach from the nearest star (alpha centauri), and back again. How far is it to the nearest star? If you could travel with light speed (300.000km/sec) it would take you 4.3 years before you arrived.

We talk about 2^128 or 2^256 which is much much much much much much much more than 2^64.

I dont think the future will find this easy.

Unless there is a mathematical breakthrough that finds the solution in a few seconds. But these problems seem to have no easy solution - the only solution is to try all combinations. But you can not be sure, maybe there is an easy solution, but we are not clever enough to spot it. But mathematicians are trying to prove that the only solution is to try every combination - which seems to be the case. However, if you find an easy solution, then you Clay institute will give you 1 million USD, and you will be world famous as one of the greatest mathematicians ever.

Google "NP-complete" for more information on this. For instance, Mine sweeper is NP-complete. Basically you need to try every possible combination - in other words, there exist no Mine Sweeper strategy that solves the game, you just need to randomly try every square. If you find a strategy that always solves the game, then you will win 1 million USD and be world famous. Google "mine sweeper np-complete" for more information.

Reply Parent Score: 2