community.linuxmint.com

Pwdhash is a browser extension (compatible with iceweasel, firefox and seamonkey) to transparently convert a user's password into a site-specific password which is not tied to the machine on which it was generated.

hashing is triggered by prefixing the password with '@@' or by using the shortcut key 'f2'. the password field in focus is replaced by the hash value. should the site be compromised, the attacker can now only see the hash of the password, not the password itself.

pwdhash does not encrypt passwords, but it makes brute-force attacks much less effective. it also means phishing sites can only steal a hash that's specific to the spoof page and useless on the site being imitated.