Add that with a story way back from 2007 – Graphics Cards – The Next Big Thing for Password Cracking? – and you’ve got yourself an interesting combo with the new offering from Amazon, distributed GPU-based resources.

Put those two stories together in true hacker style and you end up with a guy who used GPU instances on the Amazon EC2 platform to crack SHA-1 password hashes.

A German security enthusiast has used rented computing resources to crack a secure hashing algorithm (SHA-1) password.

Thomas Roth used a GPU-based rentable computer resource to run a brute force attack to crack SHA1 hashes. Encryption experts warned for at least five years SHA-1 could no longer be considered secure so what’s noteworthy about Roth’s project is not what he did or the approach he used, which was essentially based on trying every possible combination until he found a hit, but the technology he used.

What used to be the stuff of distributed computing projects with worldwide participants that took many months to bear fruit can now be done by a lone individuals in minutes and using rentable resources that cost the same price as a morning coffee to carry out the trick. Roth’s proof-of-concept exercise cost just $2. This was the amount needed to hire a bank of powerful graphics processing units to carry out the required number-crunching using the Cuda-Multiforcer.

SHA-1 was of course cracked way back in 2005, and widely reported on in 2007 – and whilst being phased out it is still used in many applications.

But then this attack isn’t really using any flaws in the algorithm – it’s just straight up hash cracking it.

The tool he used was CUDA-Multiforcer – GPU Powered High Performance Multihash Brute Forcer.

SHA-1, although it is in the process of being phased out, still forms a component of various widely-used security applications, including Secure Sockets Layer, Transport Layer Security and S/MIME protocols. Roth claims to have cracked all the hashes from a 160-bit SHA-1 hash with a password of between 1 and 6 characters in around 49 minutes. The process would create a rainbow table, allowing short and therefore automatically insecure passwords to be matched to their hash. It wouldn’t work for longer length passwords. Even so, the bigger point that rentable computing resources might be used for password hacking still stands.

Security watchers warn that the development opens up the possibility of cybercrooks using pay-as-you-go cloud computing-based parallel processing environment for their own nefarious purposes.

Chris Burchett, CTO and co-founder of the data security firm Credant, said: “It’s easy to start up a 100-node cracking cluster with just a few clicks, but if you extend the parallel processing environment by just a few factors, it becomes possible to crack passwords of most types in a relatively short timeframe.”

Cybercriminals might use stolen payment card credentials to fund their cloud cracking escapades “which means they will not be bothered about the cost involved,” he added.

Around 12 months ago, another white-hat hacker, Moxie Marlinspike, created an online Wi-Fi password-cracking service called WPAcracker.com. The $17-a-time service is able to crack a Wi-Fi password in around 20 minutes, compared to the 120 hours a dual-core PC might take to carry out the same job.

Although there’s nothing really new here, it’s still an interesting implementation of some already known techniques. As cloud/distributed computing becomes even cheaper, I’d guess we’ll be seeing more similar attacks in the future.

The original post (which precise details on how to set everything up) can be found on the blog of Thomas Roth here:

Cracking Passwords In The Cloud: Amazon’s New EC2 GPU Instances

Source: The Register

Now this is interesting a proper mathematical calculation for using cloud computing to crack passwords, now Amazon has opened up their EC2 (Elastic Compute Cloud) the cost of massive parallel processing power has come right down.

And guess what, someone thought of using it to crack passwords. It seems the cut-off would be a 12 character password as even with all lower case characters it would cost USD1.5 million to crack.

It gets exponentially cheaper as you remove each character (due to the calculation using the power of the number of characters) so a 10 character password would only cost you just over USD2000!

Forget what you’ve learned about password security. A simple pass code with nothing more than lower-case letters may be all you need – provided you use 12 characters.

That’s the conclusion of security consultant David Campbell, who calculated the cost of waging a brute-force attack on various types of passwords using cloud computing services offered by Amazon.

Based on hourly fees Amazon charges for its EC2 web service, it would cost more than $1.5m to brute force a 12-character password containing nothing more than lower-case letters a through z. But user beware, an 11-character code costs less than $60,000 to crack, and a 10-letter phrase costs less than $2,300.

Adding upper-case letters and numbers to a password offers some additional security, but not as much as you might think. Such a phrase using 10 characters would cost less than $60,000 to attack, while an 11-character code would cost roughly $2.1m. Even passwords that contain an additional 32 characters such as !@#$% are relatively cheap to crack if they are short enough. An eight-character password would cost a little more than $106,000.

I’d say adding upper case letters and numbers makes quite a difference, a 10 character passwords jumps from just over USD2000 to crack all the way up to USD60,000. That’s a factor of 30!

I’d say a 10 character password containing uppercase, lowercase, numbers and specials characters should be well into the millions and keep you fairly safe.

I did write some guidelines and tips on creating a secure password a while back, you can check it out here – Good Password Guidelines – How to Make a Strong/Secure Password.

The analysis, which Campbell posted here, builds off of research fellow security consultant Haroon Meer of SensePost presented earlier this year at the Black Hat conference. In it, he showed how EC2 could provide criminals using stolen credit cards with the equivalent of a super computer to crack encryption keys and passwords.

And that, in turn, will require new ways of thinking on the part of white hats.

“As it becomes possible now for the black hat community to get their hands on large amounts of computing power, we as security professionals are going to need to reassess threat models that we thought previously were not a factor,” said Campbell. “Using stolen credit cards, they could create a super computer that would be faster potentially than what the three-letter agencies have and they wouldn’t be paying for the CPU cycles.”

Although Amazon takes pains to ration resources it makes available to single customers, Meer showed it was possible to get around such limitations using a single credit card. Presumably, it would be even easier to bypass those controls using hundreds or thousands of stolen credit cards, something that is trivial for criminals to get a hold of. Campbell’s assumptions are based on simple arithmetic.

It’s interesting research nevertheless, I’d say Cloud Computing is only going to get more powerful and cheaper to rent so character based passwords may become completely defunct at some point in the future.

The computing power is not at the point where you have to worry about your 1024 bit RSA encryption quite yet, but it may well be in the near future as it’s already advised to use a 2048 bit key length!

Combining this platform with the abundance of stolen credit card details the blackhats have could be quite devastating.

Source: The Register