  The Facebook Social network is very famous and widely used by millions of
users all over the world. Facebook comes with high level of usability so users
can easily find their friends and connect to them, but there are security
issues related to this process where the attacker can make same-site or
cross-site profile cloning attacks to get other users data. In this paper we
will identify advanced same-site or cross-site profile cloning attacks then we
will propose a security solution to these attacks where the user must record a
voice message and answer some questions when he sends a friend request to
another user, and then the other user will listen to this message before
deciding to accept or reject the request. We implemented this solution by
developing new web application called SNKnock which is available as free
service.
