Abstract: Caller ID authentication methodology is used to authenticate call destination and detect call forwarding in a telecommunication system. Call forwarding detection is performed by the called party authentication device transmitting an authentication request message to the authentication server. The authentication request containing the source telephone number of the call and the called party telephone number. The authentication server matches the authentication request message to a calling status message transmitted by the caller party authentication device. The calling status message containing the caller telephone number and the destination telephone number. If the two messages match, the server informs the caller authentication device that the call has reached the intended party and the call destination is authentic.

Abstract: Systems and methods for caller id authentication, caller id spoof detection, call destination authentication and call forwarding detection are disclosed. Embodiments include legitimate caller ID spoofing, authenticating blocked caller ID's and revealing caller ID's to certain parties. Other embodiments utilize caller ID authentication within a list based call handling system. Applications of caller ID authentication methodology to other forms of communication source address authentication, such as email, SMS, and postal mail are described.

Abstract: Systems and methods for caller id authentication, spoof detection and list based call handling are disclosed. The caller ID authentication is performed by an authentication device connected to the calling party telephone transmitting the source and destination telephone numbers of the call to an authentication server. The called party authentication device extracts the caller ID of the incoming call and transmits the caller ID of the caller and the telephone number of the called party to the authentication server. The authentication server analyzes the transmitted information from both devices and replies with the authentication status of the caller ID to the called party authentication device. Other embodiments are disclosed where the authentication server is not available and caller ID authentication is performed in a peer-to-peer manner. In another embodiment, the concepts of active and passive certification passwords are used to maintain the integrity of the system.