NAF (Network Application Function)

Also known as: Network Application Function

In the 3GPP Generic Bootstrapping Architecture, the NAF is the application server that consumes a GBA-derived key (Ks_NAF) to authenticate a UE without holding long-term subscriber credentials itself. The NAF fetches the key material from the BSF over the Zn/Zn' reference point after the UE has bootstrapped, and uses it to secure the application session.

Categories: Security ControlsProtocols and StandardsEncryption and Cryptography

NAF in context

Security controls span signaling firewalls (SS7/Diameter/GTP screening), transport encryption (IPsec, TLS, PRINS), identity and access on OSS/BSS, and monitoring at both packet and log level. Controls are audited against GSMA FS.11/FS.19/FS.20/FS.36.

Telecom security is written into standards from 3GPP, GSMA, ETSI, IETF and ITU-T. Understanding which body owns which specification, and how they interlock, is essential for both design and audit work.

To place NAF in the wider telecom-security picture, review N8, SRTP, GBA, HKDF, XMPP and DTLS-SRTP: each entry cross-references back to this page so you can walk the topic in either direction.

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