When I login the hotmail, I got a 64 character long string as part of the URL and it changes each time I login. Also when I login in Yahoo email, there is a 13 character long random string generated. Can someone tell me what purpose they serve? Thanks.
I am just wondering if it's better if I change the all the user IDs in my system from auto_increment to a encrypted 32 or 64 long string.
