Aspects of the disclosure relate to multicomputer processing and authentication of user data associated with telephone calls. A call security assessment computing platform may receive data associated with a telephone call made from a user computing device. Subsequently, the call security assessment computing platform may parse the received data to identify header information in a Session Initial Protocol (SIP) header. The platform then may analyze the header information to generate a call fingerprint for the telephone call. This call fingerprint may then be transmitted to one or more call authentication computing platforms, which return one or more call security responses that may further characterize security features of the telephone call. The call fingerprint and the call security responses may then be used to determine a call security score, which may be transmitted in a notification to a call handling system in order to adjust how the call is handled.