Its likely that you will have to provide detailed info to Yahoo as I had to when my account was phished. I eventually wore down on Yahoo and got my account back when they asked me what my new alternate email will be to send the password to because my old alternate email went out of business and they verified this. I did also notice on my account that they do not show your b-day and other accoutn info so the hacker does not see that. It makes it easier to retrace your account to the real account holder so they can send you another password to your alternate email. BTW, did you try retrieving another password using your alternate email?