Password crackers have a surprising secret weapon

Researchers at the Georgia Tech Research Institute have found an unexpected tool for brute-force attacks on password-protected systems. Their findings: A seven character password is "hopelessly inadequate."

Among the oft-cited weaknesses in using passwords for authentication are that people choose bad, easily guessed passwords, such as “123456” or, even, “password.”

But even carefully chosen passwords are not enough, at least if they are too short, according to researchers at the Georgia Tech Research Institute. The reason: graphics processing units, which are powerful enough to conduct quick, effective brute-force attacks on password-protected systems.

GPUs traditionally have been used in graphics cards to render screen displays on PCs. But they also can be used to accelerate some applications, especially those involving floating-point operations. Apple’s Snow Leopard and Windows 7 operating systems are designed to hand off some processing chores to the GPU.

In a post describing their research, the GTRI team (researchers Joshua Davis and Richard Boyd, and undergraduate researcher Carl Mastrangelo) said they have been using a commonly available graphics processor to test password strength.


Related stories

Revealed: Our picks for best password strategies

Password management’s secret ingredient


"Right now we can confidently say that a seven-character password is hopelessly inadequate,” Boyd said in the post, “and as GPU power continues to go up every year, the threat will increase."

The researchers pointed out that GPUs have been amped-up over the years to handle increasingly sophisticated computer games, and in the process have achieved the power of a mini-supercomputer. Some GPUs today, even those that typically cost less than $500, can process information at a rate of nearly 2 teraflops, or two trillion floating-point operations per second. Ten years ago, the fastest supercomputer in the world, built at a cost of $110 million, ran at about 7 teraflops.

Developers began adapting them to other uses after Nvidia – one of two companies, along with AMD’s ATI, that control essentially the entire GPU market – in 2007 released a software development kit that allowed developers to program a GPU using the C programming language, the researchers said. “If you can write a C program, you can program a GPU now,” Boyd said.

And one of the programs they can be used for is password-cracking.

Brute-force attacks, in which a program tries to guess every possible combination until the right one turns up, have been around a long time. But the relatively new ability to use GPUs, which are designed as parallel processors, for brute-force attacks could put a lot of password-cracking power into the hands of a lot of people. Some of whom might not be honest.

The length of a password is important in preventing cracking, Davis said in the post. Any password with fewer than 12 letters, numbers and special characters will soon be ineffective, if it’s not already. Like many readers who responded to our request in May for password tips, he recommended pass phrases – sentences, including upper and lower case characters, symbols and numbers – as a way to avoid having passwords cracked.

Many Web sites and networks defend against brute force attacks already by limiting the number of incorrect log-in attempts, blocking out users after a set number of failed attempts. The downside of the approach is that an attacker could cause a denial-of-service attack by deliberately locking out authorized users, according to the University of Virginia’s System Administrator Database. An attacker also could use the responses from lock-outs to determine the names of authorized users, because only legitimate accounts can be locked out.

Agencies have gradually been moving toward two-factor authentication systems, which take some of the pressure off of passwords. As the processing units available to attackers become increasingly powerful, two-factor systems could become even more necessary.

X
This website uses cookies to enhance user experience and to analyze performance and traffic on our website. We also share information about your use of our site with our social media, advertising and analytics partners. Learn More / Do Not Sell My Personal Information
Accept Cookies
X
Cookie Preferences Cookie List

Do Not Sell My Personal Information

When you visit our website, we store cookies on your browser to collect information. The information collected might relate to you, your preferences or your device, and is mostly used to make the site work as you expect it to and to provide a more personalized web experience. However, you can choose not to allow certain types of cookies, which may impact your experience of the site and the services we are able to offer. Click on the different category headings to find out more and change our default settings according to your preference. You cannot opt-out of our First Party Strictly Necessary Cookies as they are deployed in order to ensure the proper functioning of our website (such as prompting the cookie banner and remembering your settings, to log into your account, to redirect you when you log out, etc.). For more information about the First and Third Party Cookies used please follow this link.

Allow All Cookies

Manage Consent Preferences

Strictly Necessary Cookies - Always Active

We do not allow you to opt-out of our certain cookies, as they are necessary to ensure the proper functioning of our website (such as prompting our cookie banner and remembering your privacy choices) and/or to monitor site performance. These cookies are not used in a way that constitutes a “sale” of your data under the CCPA. You can set your browser to block or alert you about these cookies, but some parts of the site will not work as intended if you do so. You can usually find these settings in the Options or Preferences menu of your browser. Visit www.allaboutcookies.org to learn more.

Sale of Personal Data, Targeting & Social Media Cookies

Under the California Consumer Privacy Act, you have the right to opt-out of the sale of your personal information to third parties. These cookies collect information for analytics and to personalize your experience with targeted ads. You may exercise your right to opt out of the sale of personal information by using this toggle switch. If you opt out we will not be able to offer you personalised ads and will not hand over your personal information to any third parties. Additionally, you may contact our legal department for further clarification about your rights as a California consumer by using this Exercise My Rights link

If you have enabled privacy controls on your browser (such as a plugin), we have to take that as a valid request to opt-out. Therefore we would not be able to track your activity through the web. This may affect our ability to personalize ads according to your preferences.

Targeting cookies may be set through our site by our advertising partners. They may be used by those companies to build a profile of your interests and show you relevant adverts on other sites. They do not store directly personal information, but are based on uniquely identifying your browser and internet device. If you do not allow these cookies, you will experience less targeted advertising.

Social media cookies are set by a range of social media services that we have added to the site to enable you to share our content with your friends and networks. They are capable of tracking your browser across other sites and building up a profile of your interests. This may impact the content and messages you see on other websites you visit. If you do not allow these cookies you may not be able to use or see these sharing tools.

If you want to opt out of all of our lead reports and lists, please submit a privacy request at our Do Not Sell page.

Save Settings
Cookie Preferences Cookie List

Cookie List

A cookie is a small piece of data (text file) that a website – when visited by a user – asks your browser to store on your device in order to remember information about you, such as your language preference or login information. Those cookies are set by us and called first-party cookies. We also use third-party cookies – which are cookies from a domain different than the domain of the website you are visiting – for our advertising and marketing efforts. More specifically, we use cookies and other tracking technologies for the following purposes:

Strictly Necessary Cookies

We do not allow you to opt-out of our certain cookies, as they are necessary to ensure the proper functioning of our website (such as prompting our cookie banner and remembering your privacy choices) and/or to monitor site performance. These cookies are not used in a way that constitutes a “sale” of your data under the CCPA. You can set your browser to block or alert you about these cookies, but some parts of the site will not work as intended if you do so. You can usually find these settings in the Options or Preferences menu of your browser. Visit www.allaboutcookies.org to learn more.

Functional Cookies

We do not allow you to opt-out of our certain cookies, as they are necessary to ensure the proper functioning of our website (such as prompting our cookie banner and remembering your privacy choices) and/or to monitor site performance. These cookies are not used in a way that constitutes a “sale” of your data under the CCPA. You can set your browser to block or alert you about these cookies, but some parts of the site will not work as intended if you do so. You can usually find these settings in the Options or Preferences menu of your browser. Visit www.allaboutcookies.org to learn more.

Performance Cookies

We do not allow you to opt-out of our certain cookies, as they are necessary to ensure the proper functioning of our website (such as prompting our cookie banner and remembering your privacy choices) and/or to monitor site performance. These cookies are not used in a way that constitutes a “sale” of your data under the CCPA. You can set your browser to block or alert you about these cookies, but some parts of the site will not work as intended if you do so. You can usually find these settings in the Options or Preferences menu of your browser. Visit www.allaboutcookies.org to learn more.

Sale of Personal Data

We also use cookies to personalize your experience on our websites, including by determining the most relevant content and advertisements to show you, and to monitor site traffic and performance, so that we may improve our websites and your experience. You may opt out of our use of such cookies (and the associated “sale” of your Personal Information) by using this toggle switch. You will still see some advertising, regardless of your selection. Because we do not track you across different devices, browsers and GEMG properties, your selection will take effect only on this browser, this device and this website.

Social Media Cookies

We also use cookies to personalize your experience on our websites, including by determining the most relevant content and advertisements to show you, and to monitor site traffic and performance, so that we may improve our websites and your experience. You may opt out of our use of such cookies (and the associated “sale” of your Personal Information) by using this toggle switch. You will still see some advertising, regardless of your selection. Because we do not track you across different devices, browsers and GEMG properties, your selection will take effect only on this browser, this device and this website.

Targeting Cookies

We also use cookies to personalize your experience on our websites, including by determining the most relevant content and advertisements to show you, and to monitor site traffic and performance, so that we may improve our websites and your experience. You may opt out of our use of such cookies (and the associated “sale” of your Personal Information) by using this toggle switch. You will still see some advertising, regardless of your selection. Because we do not track you across different devices, browsers and GEMG properties, your selection will take effect only on this browser, this device and this website.