Security Challenges of the 3GPP 5G Service Based Architecture

3GPP is currently finalizing the first publication of 5G specifications in their Release 15. Several new features and concepts are introduced to the radio interface and the core network in order to enhance the softwarization and virtualization of functional entities in the mobile core network. One of the driving new concepts is the service-based architecture (SBA). Service concepts and technologies are already well established in the area of Internet-based platforms and applications. With the 3GPP 5G SBA, flexible and on-demand service composition - even across organizational boundaries - provides a new level of flexibility and business opportunities to the mobile industry. However, this type of service orientation comes with new security implications that have not been present to their full extent in previous mobile network generations. This article introduces the foundational security concepts and technologies of SBA in 3GPP 5G, focusing mainly on non-roaming scenarios, and discusses security challenges arising from these architectural changes.