Call authentication system and method for blocking unwanted calls

A system for blocking unwanted calls, the system comprising non-transitory computer-readable media such that when executed by a processor is operable to:

• intercept a call being routed from a calling device to a receiving device, the intercepting occurring prior to the call being presented to the receiving device for an answer;
• determine further routing of the intercepted call by comparing parameters of the intercepted call to one or more lists;
• if it is determined that the call should be authenticated, send an authentication challenge to the calling device,
• if a response is received to the authentication challenge, determine whether the response is correct;
• if the response is correct, route the call to the receiving device;
• and
• update the one or more lists if no response to the authentication challenge is received from the calling device, the update used for future calls, wherein the failure to respond is shared with others in a community for a consideration of heightened scrutiny for the calling device.