One of the password programs Young's team is using, John the Ripper, is trying some 700 to 800 million word combinations a second. Other tools Young is using are trying as many as 5 billion combinations per second, an astounding figure. So far, they've only decoded around 50,000 LinkedIn hashes.
Young's next idea is try to use combinations of financial and business-related words. Because LinkedIn has many business users, it may be more likely that those types of phrases would be used.
In another innovation, Young's colleague Joshua Dustin recently wrote a program that mines Twitter for more word combinations. The script connects to Twitter and pulls 500 messages related to a desired term, then delivers all of the words in a list.
Dustin wrote on his blog that he used the method against hashes generated by the MD5 algorithm from the MilitarySingles.com breach. Of the 4,400 unique words pulled from Twitter, 1,978 passwords were revealed using John the Ripper cracking program, he wrote.
"This is a very small example of what can be done to generate more relevant password lists using twitter/websites/social media to supply you with the related words," he wrote.
The difficulty in cracking some of the LinkedIn passwords may be of some relief to users, even though LinkedIn said it doesn't believe that e-mail addresses used to login into accounts with passwords have been released.
"These are tough, tough passwords," Young said.
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