There is a way to improve the security of weakly hashed passwords without having to ask the user to change their password - http://blog.jgc.org/2012/06/one-way-

There is a way to improve the security of weakly hashed passwords without having to ask the user to change their password - http://blog.jgc.org/2012/06/one-way-to-fix-your-rubbish-password.html http://blog.jgc.org/2012/06/one-way-to-fix-your-rubbish-pass...