Entries Tagged "cracking"

Page 2 of 5

Scientists Banned from Revealing Details of Car-Security Hack

The UK has banned researchers from revealing details of security vulnerabilities in car locks. In 2008, Phillips brought a similar suit against researchers who broke the Mifare chip. That time, they lost. This time, Volkswagen sued and won.

This is bad news for security researchers. (Remember back in 2001 when security researcher Ed Felten sued the RIAA in the US to be able to publish his research results?) We’re not going to improve security unless we’re allowed to publish our results. And we can’t start suppressing scientific results, just because a big corporation doesn’t like what it does to their reputation.

EDITED TO ADD (8/14): Here’s the ruling.

Posted on August 1, 2013 at 6:37 AM • View Comments

A Really Good Article on How Easy it Is to Crack Passwords

Ars Technica gave three experts a 16,000-entry encrypted password file, and asked them to break them. The winner got 90% of them, the loser 62%—in a few hours.

The list of “plains,” as many crackers refer to deciphered hashes, contains the usual list of commonly used passcodes that are found in virtually every breach involving consumer websites. “123456,” “1234567,” and “password” are there, as is “letmein,” “Destiny21,” and “pizzapizza.” Passwords of this ilk are hopelessly weak. Despite the additional tweaking, “p@$$word,” “123456789j,” “letmein1!,” and “LETMEin3” are equally awful….

As big as the word lists that all three crackers in this article wielded—close to 1 billion strong in the case of Gosney and Steube—none of them contained “Coneyisland9/,” “momof3g8kids,” or the more than 10,000 other plains that were revealed with just a few hours of effort. So how did they do it? The short answer boils down to two variables: the website’s unfortunate and irresponsible use of MD5 and the use of non-randomized passwords by the account holders.

The article goes on to explain how dictionary attacks work, how well they do, and the sorts of passwords they find.

Steube was able to crack “momof3g8kids” because he had “momof3g” in his 111 million dict and “8kids” in a smaller dict.

“The combinator attack got it! It’s cool,” he said. Then referring to the oft-cited xkcd comic, he added: “This is an answer to the batteryhorsestaple thing.”

What was remarkable about all three cracking sessions were the types of plains that got revealed. They included passcodes such as “k1araj0hns0n,” “Sh1a-labe0uf,” “Apr!l221973,” “Qbesancon321,” “DG091101%,” “@Yourmom69,” “ilovetofunot,” “windermere2313,” “tmdmmj17,” and “BandGeek2014.” Also included in the list: “all of the lights” (yes, spaces are allowed on many sites), “i hate hackers,” “allineedislove,” “ilovemySister31,” “iloveyousomuch,” “Philippians4:13,” “Philippians4:6-7,” and “qeadzcwrsfxv1331.” “gonefishing1125” was another password Steube saw appear on his computer screen. Seconds after it was cracked, he noted, “You won’t ever find it using brute force.”

Great reading, but nothing theoretically new. Ars Technica wrote about this last year, and Joe Bonneau wrote an excellent commentary.

Password cracking can be evaluated on two nearly independent axes: power (the ability to check a large number of guesses quickly and cheaply using optimized software, GPUs, FPGAs, and so on) and efficiency (the ability to generate large lists of candidate passwords accurately ranked by real-world likelihood using sophisticated models).

I wrote about this same thing back in 2007. The news in 2013, such as it is, is that this kind of thing is getting easier faster than people think. Pretty much anything that can be remembered can be cracked.

If you need to memorize a password, I still stand by the Schneier scheme from 2008:

So if you want your password to be hard to guess, you should choose something that this process will miss. My advice is to take a sentence and turn it into a password. Something like “This little piggy went to market” might become “tlpWENT2m”. That nine-character password won’t be in anyone’s dictionary. Of course, don’t use this one, because I’ve written about it. Choose your own sentence—something personal.

Until this very moment, these passwords were still secure:

  • WIw7,mstmsritt… = When I was seven, my sister threw my stuffed rabbit in the toilet.
  • Wow…doestcst::amazon.cccooommm = Wow, does that couch smell terrible.
  • Ltime@go-inag~faaa! = Long time ago in a galaxy not far away at all.
  • uTVM,TPw55:utvm,tpwstillsecure = Until this very moment, these passwords were still secure.

You get the idea. Combine a personally memorable sentence, some personal memorable tricks to modify that sentence into a password, and create a long-length password.

Better, though, is to use random unmemorable alphanumeric passwords (with symbols, if the site will allow them), and a password manager like Password Safe to store them. (If anyone wants to port it to the Mac, iPhone, iPad, or Android, please contact me.) This article does a good job of explaining the same thing. David Pogue likes Dashlane, but doesn’t know if it’s secure.

In related news, Password Safe is a candidate for July’s project-of-the-month on SourceForge. Please vote for it.

EDITED TO ADD (6/7): As a commenter noted, none of this is useful advice if the site puts artificial limits on your password.

EDITED TO ADD (6/14): Various ports of Password Safe. I know nothing about them, nor can I vouch for their security.

Analysis of the xkcd scheme.

Posted on June 7, 2013 at 6:41 AM • View Comments

Al Qaeda Steganography

The reports are still early, but it seems that a bunch of terrorist planning documents were found embedded in a digital file of a porn movie.

Several weeks later, after laborious efforts to crack a password and software to make the file almost invisible, German investigators discovered encoded inside the actual video a treasure trove of intelligence—more than 100 al Qaeda documents that included an inside track on some of the terror group’s most audacious plots and a road map for future operations.

Posted on May 2, 2012 at 12:41 PM • View Comments

WPA Cracking in the Cloud

It’s a service:

The mechanism used involves captured network traffic, which is uploaded to the WPA Cracker service and subjected to an intensive brute force cracking effort. As advertised on the site, what would be a five-day task on a dual-core PC is reduced to a job of about twenty minutes on average. For the more “premium” price of $35, you can get the job done in about half the time. Because it is a dictionary attack using a predefined 135-million-word list, there is no guarantee that you will crack the WPA key, but such an extensive dictionary attack should be sufficient for any but the most specialized penetration testing purposes.

[…]

It gets even better. If you try the standard 135-million-word dictionary and do not crack the WPA encryption on your target network, there is an extended dictionary that contains an additional 284 million words. In short, serious brute force wireless network encryption cracking has become a retail commodity.

FAQ here.

In related news, there might be a man-in-the-middle attack possible against the WPA2 protocol. Man-in-the-middle attacks are potentially serious, but it depends on the details—and they’re not available yet.

EDITED TO ADD (8/8): Details about the MITM attack.

Posted on July 27, 2010 at 6:43 AM • View Comments

Cryptography Broken on American Military Attack Video

Any ideas?

At a news conference at the National Press Club, WikiLeaks said it had acquired the video from whistle-blowers in the military and viewed it after breaking the encryption code. WikiLeaks released the full 38-minute video as well as a 17-minute edited version.

And this quote from the WikiLeaks Twitter feed on Feb 20th:

Finally cracked the encryption to US military video in which journalists, among others, are shot. Thanks to all who donated $/CPUs.

Surely this isn’t NSA-level encryption. But what is it?

Note that this is intended to be a discussion about the cryptanalysis, not about the geopolitics of the event.

EDITED TO ADD (4/13): It was a dictionary attack.

Posted on April 7, 2010 at 1:37 PM • View Comments

Choosing a Bad Password Has Real-World Consequences

Oops:

Wikileaks has cracked the encryption to a key document relating to the war in Afghanistan. The document, titled “NATO in Afghanistan: Master Narrative”, details the “story” NATO representatives are to give to, and to avoid giving to, journalists.

An unrelated leaked photo from the war: a US soldier poses with a dead Afghani man in the hills of Afghanistan

The encrypted document, which is dated October 6, and believed to be current, can be found on the Pentagon Central Command (CENTCOM) website.

Posted on March 9, 2009 at 1:19 PM • View Comments

Another Password Analysis

Here’s an analysis of 30,000 passwords from phpbb.com, similar to my analysis of 34,000 MySpace passwords:

The striking different between the two incidents is that the phpbb passwords are simpler. MySpace requires that passwords “must be between 6 and 10 characters, and contain at least 1 number or punctuation character.” Most people satisfied this requirement by simply appending “1” to the ends of their passwords. The phpbb site has no such restrictions—the passwords are shorter and rarely contain anything more than a dictionary word.

Seems like we still can’t choose good passwords. Conficker.B exploits this, trying about 200 common passwords to help spread itself.

Posted on February 20, 2009 at 7:31 AM • View Comments

Balancing Security and Usability in Authentication

Since January, the Conficker.B worm has been spreading like wildfire across the Internet: infecting the French Navy, hospitals in Sheffield, the court system in Houston, and millions of computers worldwide. One of the ways it spreads is by cracking administrator passwords on networks. Which leads to the important question: Why in the world are IT administrators still using easy-to-guess passwords?

Computer authentication systems have two basic requirements. They need to keep the bad guys from accessing your account, and they need to allow you to access your account. Both are important, and every authentication system is a balancing act between the two. Too little security, and the bad guys will get in too easily. But if the authentication system is too complicated, restrictive, or hard to use, you won’t be able to—or won’t bother to—use it.

Passwords are the most common authentication system, and a good place to start. They’re very easy to implement and use, which is why they’re so popular. But as computers have become faster, password guessing has become easier. Most people don’t choose passwords that are complicated enough to remain secure against modern password-guessing attacks. Conficker.B is even less clever; it just tries a list of about 200 common passwords.

To combat password guessing, many systems force users to choose harder-to-guess passwords—requiring minimum lengths, non alpha-numeric characters, etc.—and change their passwords more frequently. The first makes guessing harder, and the second makes a guessed password less valuable. This, of course, makes the system more annoying, so users respond by writing their passwords down and taping them to their monitors, or simply forgetting them more often. Smarter users write them down and put them in their wallets, or use a secure password database like Password Safe.

Users forgetting their passwords can be expensive—sysadmins or customer service reps have to field phone calls and reset passwords—so some systems include a backup authentication system: a secret question. The idea is that if you forget your password, you can authenticate yourself with some personal information that only you know. Your mother’s maiden name was traditional, but these days there are all sorts of secret questions: your favourite schoolteacher, favourite colour, street you grew up on, name of your first pet, and so on. This might make the system more usable, but it also makes it much less secure: answers can be easily guessable, and are often known by people close to you.

A common enhancement is a one-time password generator, like a SecurID token. This is a small device with a screen that displays a password that changes automatically once a minute. Adding this is called two-factor authentication, and is much more secure, because this token—”something you have”—is combined with a password—”something you know.” But it’s less usable, because the tokens have to be purchased and distributed to all users, and far too often it’s “something you lost or forgot.” And it costs money. Tokens are far more frequently used in corporate environments, but banks and some online gaming worlds have taken to using them—sometimes only as an option, because people don’t like them.

In most cases, how an authentication system works when a legitimate user tries to log on is much more important than how it works when an impostor tries to log on. No security system is perfect, and there is some level of fraud associated with any of these authentication methods. But the instances of fraud are rare compared to the number of times someone tries to log on legitimately. If a given authentication system let the bad guys in one in a hundred times, a bank could decide to live with the problem—or try to solve it in some other way. But if the same authentication system prevented legitimate customers from logging on even one in a thousand times, the number of complaints would be enormous and the system wouldn’t survive one week.

Balancing security and usability is hard, and many organizations get it wrong. But it’s also evolving; organizations needing to tighten their security continue to push more involved authentication methods, and more savvy Internet users are willing to accept them. And certainly IT administrators need to be leading that evolutionary change.

A version of this essay was originally published in The Guardian.

Posted on February 19, 2009 at 1:44 PM • View Comments

1 2 3 4 5

Sidebar photo of Bruce Schneier by Joe MacInnis.