Following the revelation that hackers managed to compromise 8 million passwords from social sites LinkedIn and eHarmony, worried users will no doubt be concerned that their own accounts were among the ones which were breached.

While the companies have promised to notify all users whose passwords have been compromised, experts have warned that the hackers responsible for the beach may have more, as yet unpublished, passwords in their possession.

Obviously, users are now going to be even more worried that their accounts were among those that were compromised. Responding to the situation, password management firm LastPass.com has created two simple tools for LinkedIn and eHarmony users to check on the integrity of their passwords.

Before using the tools to check if they’ve been compromised, LastPass advises users to change their passwords first, especially if they use that password with any other social media or email accounts.

To check your Linkedin password, go here.

To check your eHarmony password, go here.

LastPass affirms that using their tool will not compromise any password further, as it works by computing the SHA-1 hash of the password, then sending the hash to LastPass before checking it against the list of known, compromised passwords. The hash is the result of a one-way mathematical algorithm that’s incredibly difficult to reverse – essentially, it reconstructs the password into a character sequence that is so complex that hackers are unlikely to be able to reverse it. The password itself is not sent to LastPass, and nor is the hash of the password stored or logged in their system.

The only risk is with those passwords that use simple words or names found in a dictionary. In these cases, LastPass warn that it may be possible to work out the original password based on the SHA-1 hash. Indeed, this is the reason for all the fuss – it’s far easier to reverse the hash of a simple password than a more complex one that uses a ‘random’ sequence of characters.