More than 60% of the unique hashed passwords that were accessed by hackers from a LinkedIn password database and posted online this week have already been cracked, according to security firm Sophos.
It’s very likely the remaining passwords have also been cracked, said security researcher Chester Wisniewski late Wednesday.
In all, a total of 6.5 million hashed password believed to belong to LinkedIn members was posted on a Russian hacker forum earlier this week. The crooks posted the data in an effort to get help in cracking the passwords.
Sophos said it identified about 5.8 million hashed passwords as unique.
Based on an analysis of the 118MB password dump, Wisniewski said close to 3.5 million of the unique passwords had been cracked and made available in plain text by late last night. It’s only a matter of time before the remaining passwords are similarly cracked using automated password guessing tools, he added.
The speed at which so many hashed passwords were cracked underscores the weakness of the passwords protection scheme used by LinkedIn, Wisniewski said.
The breached LinkedIn member passwords were all hashed, or masked, using a hashing protocol known as SHA-1.
Though SHA-1 offers a degree of protection against password cracking attempts, the protocol is by no means foolproof.
Therefore, many organizations theses day use a process known as salting — where a random string of characters are appended to a password before it is hashed– to make password cracking much harder. The process ensures that even if two passwords are identical, their hashes will be unique.
Salting is considered something of a best practice for protecting passwords, especially those used by employees of large companies.
That LinkedIn apparently chose to protect passwords using just SHA-1 is disappointing, Wisniewski said. “They chose a moderate security method. For an organization as large as LinkedIn, I would expect better,” he said.
The worst policy for companies is to store passwords in clear text, experts say.
Source: computer world