what make you think that this "fb_sig=a7df4d0e7fc104617a9e7e5121c2aad0"
is an encrypting. and if you really did find out their encrypt. You woudlent be able to hack others accounts. Cause the password file, userfile is stored on a server and you cant find others passwords just using tramper? you are an complete idiot if you think so.
so the only way to do what you are talking about is to hack the hole server your self.
so good luck with that.