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