QUICUP: Secure User Plane Tunneling for Cellular Networks

Integrating new services and applications like edge computing in current and future generations of cellular networks leads to new challenges regarding the security and privacy of user plane traffic. The GPRS Tunneling Protocol in the user plane (GTP-U) was first introduced within 2G networks and is still used in 5G and beyond cellular networks. This protocol lacks integrated security mechanisms such as tunnel endpoint authentication or integrity validation of encapsulated user data and depends on deployment of IPSec and implementation-specific validation procedures to attain baseline security guarantees. Furthermore, GTP-U provides limited extensibility, hindering advanced transport layer optimizations necessary for modern network demands.In this paper, we propose QUICUP, a novel tunneling solution for GTP-U traffic based on QUIC. QUIC enhances web communication through integrated application-layer encryption which enables strong binding to user sessions and significantly reduces the attack surface on shared network infrastructure.Our research presents a mapping between GTP-U and QUICUP, and the prototypical implementation within a 5G core network demonstrates QUIC’s capability to effectively replace GTP-U as a tunneling protocol in mobile networks. Ultimately, the proposed transition aligns with ongoing industry movements toward protocol modernization and to better accommodate security and privacy within mobile networks.