5G-GUTI (5G Globally Unique Temporary Identifier)

In telecom networks, the 5G-GUTI is a temporary subscriber identifier assigned by the AMF that is used in place of the SUPI on the radio interface to limit identity exposure. Frequent 5G-GUTI reallocation reduces the ability of attackers to track a subscriber over time.

Categories: Radio Access NetworkCore NetworkIdentity and Subscriber

5G-GUTI in context

The radio access network is the layer where mobile devices attach to the operator's infrastructure. Attacks in this layer include IMSI catching, rogue base stations, downgrade attacks and jamming, and defenses hinge on mutual authentication, integrity-protected signaling and Open RAN supply-chain hygiene.

The mobile core is where subscriber sessions, mobility and policy live. In 4G it is the EPC (MME, HSS, S/PGW); in 5G it is the Service-Based Architecture with AMF, SMF, UPF, AUSF, UDM and the NRF. Core exposure is the difference between a single-subscriber leak and a fleet-wide breach.

To place 5G-GUTI in the wider telecom-security picture, review TMSI, UPF, MNO, Confidentiality, Encryption and VRAN.

Related terms

Related topic hubs

  • 5G Security 5G SBA, SEPP, SUCI, 5G-AKA, N32 and service-based interface security.
  • 5G NEF Security Network Exposure Function security in the 5G core.
  • NAS Security Non-Access Stratum security, integrity and ciphering algorithms.
  • 5G Penetration Testing Pentesting the 5G core, SBA, SEPP, and gNB interfaces.

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