Introduction

Network Access Security can be seen as the “realisation” of the network. Almost all communication inside and outside the 5G Core uses this protocol. It is based on the measure already used in 4G called “air interface encryption”. This measure ensures confidentiality and with 5G, Network Access Security also supports integrity protection. Thus providing full-fledged protection for the communication happening over the air in the User Plane. Network Access Security can be split up into three different areas: Identification, Authentication and Key Agreement and Security Activation. On the left image below, you can see the flow of the communication in a simplified way. The right image shows how the communication lays between the UE, gNodeB and Core Network.