Reallocation of Temporary Identities: Applying 5G Cybersecurity and Privacy Capabilities

Published

March 19, 2026

Author(s)

Michael Bartock, Jeffrey Cichonski, Murugiah Souppaya, Karen Kent, Parisa Grayeli, Sanjeev Sharma

Abstract

This white paper is part of a series called Applying 5G Cybersecurity and Privacy Capabilities, which covers 5G cybersecurity- and privacy-supporting capabilities that were implemented as part of the 5G Cybersecurity project at the National Cybersecurity Center of Excellence (NCCoE). This white paper provides additional details regarding how 5G protects subscriber identities (IDs). It focuses on how the network reallocates temporary IDs to protect users from being identified and located by an attacker. Unlike previous generations of cellular systems, new requirements in 5G explicitly define when the temporary ID must be reallocated (refreshed). 5G network operators should be aware of how this standards-defined security capability protects their users and subscribers. Operators should ensure that their 5G technologies are refreshing temporary identities as described in the 5G standards.

Citation

NIST Cybersecurity White Papers (CSWP) - 36C

Report Number

36C

Pub Type

NIST Pubs

Download Paper

https://doi.org/10.6028/NIST.CSWP.36C

Local Download

Keywords

3GPP, 5G, cybersecurity, privacy, reallocation of temporary identities (IDs), Subscription Concealed Identifier (SUCI), Subscription Permanent Identifier (SUPI), Globally Unique Temporary user equipment Identity (GUTI)

Citation

Bartock, M. , Cichonski, J. , Souppaya, M. , Kent, K. , Grayeli, P. and Sharma, S. (2026), Reallocation of Temporary Identities: Applying 5G Cybersecurity and Privacy Capabilities, NIST Cybersecurity White Papers (CSWP), National Institute of Standards and Technology, Gaithersburg, MD, [online], https://doi.org/10.6028/NIST.CSWP.36C, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=961424 (Accessed March 20, 2026)