Securing SS7 Telecommunications Networks

Signaling System 7 (SS7) deflnes the network architecture, conflguration and message transport protocol for Public Telephone Networks (PTNs). SS7 was originally designed for a closed telecommunications community, and therefore possesses limited authentication facilities. Dereg- ulation coupled with PTN convergence with the Internet and wireless networks signiflcantly increase vulnerabilities, enabling attackers to perpetrate fraud, interception and in- terruption on a potentially massive scale. This paper analyzes vulnerabilities in SS7 networks and presents an attack taxonomy. The architecture of a system for detecting and responding to SS7 network attacks is also described.