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NR-AS Security Complete

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In 5G New Radio (NR) networks, the "NR-AS Security Complete" procedure is a technical process that signifies the successful establishment of security between the User Equipment (UE) and the network's Access Stratum (AS). This procedure is critical for ensuring the confidentiality, integrity, and authenticity of communication between the UE and the network. Here's a detailed technical explanation of the NR-AS Security Complete procedure:

Background: Security in 5G NR:

  • Security is a fundamental aspect of any wireless communication system, and in 5G NR, it plays a crucial role in protecting user data and network resources.
  • The AS Security procedures are responsible for establishing and maintaining security between the UE and the network.

Security Context Establishment:

  1. Before the NR-AS Security Complete procedure begins, the UE and the network establish a security context. This context includes parameters such as security keys, algorithms, and security modes to be used for secure communication.
  2. The security context is typically established during the initial network registration and connection setup procedures.

Security Functions:

  1. The AS Security procedures in NR involve several key functions, including:
  • Authentication: The UE and the network mutually authenticate each other's identities to ensure that they are communicating with legitimate entities.
  • Key Agreement: The UE and the network derive shared encryption and integrity protection keys that will be used for securing data traffic.
  • Ciphering: Data is encrypted using the agreed-upon encryption keys to ensure confidentiality.
  • Integrity Protection: Integrity protection mechanisms ensure that data has not been tampered with during transmission.
  • Replay Protection: Measures are in place to detect and discard duplicate or replayed messages, which can be a security threat.

Security Configuration:

  1. The network configures the security parameters for the UE, including the security algorithms, security keys, and security modes.
  2. These parameters are transmitted securely to the UE during the security context establishment.

UE Initialization:

  1. The UE initializes its security functions, using the configured security parameters.

Security Activation:

  1. As the UE communicates with the network, it activates security measures to protect its communication.
  • For example, data transmitted from the UE to the network is encrypted using the agreed-upon encryption keys.
  • Data received from the network is decrypted and integrity-protected using the same keys.

AS Security Complete Message:

  1. When the UE has successfully established the security measures and can communicate securely with the network, it generates an "NR-AS Security Complete" message.
  2. This message signifies that the UE has completed the AS security establishment process and is ready for secure communication with the network.

Message Transmission to Network:

  1. The UE sends the "NR-AS Security Complete" message to the network, indicating that it has successfully established security and is in a secure operational state.

Network Confirmation:

  1. Upon receiving the "NR-AS Security Complete" message from the UE, the network confirms the successful establishment of security for the UE.

Secure Data Communication:

  1. With security successfully established, the UE and the network can now exchange data securely, ensuring the confidentiality and integrity of the communication.

Ongoing Security:

  1. Security is maintained throughout the UE's communication session with the network.
  2. Security associations and keys may be periodically refreshed or updated to maintain the level of security.

The NR-AS Security Complete procedure is crucial for protecting the confidentiality and integrity of data exchanged between the UE and the network in 5G NR networks. It ensures that the necessary security measures are successfully initialized and that both the UE and the network are in a secure operational state for communication.