5G • Security
SEPP
Security Edge Protection Proxy
The security gateway terminating inter-PLMN signaling between 5G roaming partner networks, providing end-to-end message encryption and filtering.
Technical Explanation
In 2G/3G/4G, SS7 and Diameter roaming interconnects suffered from critical spoofing and tracking vulnerabilities. In 5G, inter-PLMN communication over the N32 interface is mediated by the SEPP. The SEPP provides mutual authentication, authorization, and Application Layer Security (PRINS - Protocol for N32 Interconnect Security) using JSON Web Encryption (JWE) and JSON Web Signatures (JWS) to protect sensitive subscriber and network topology headers while allowing IPX roaming hubs to inspect routing headers.
Key Functions
- Application layer security (JWE/JWS) for inter-operator 5G roaming signaling
- Topology hiding and sensitive IE masking between visiting and home PLMNs
- Protection against eavesdropping, spoofing, and malicious roaming injection
- Policing and rate-limiting of incoming inter-PLMN HTTP/2 requests
Specifications
3GPP TS 33.501 Section 5.9, TS 29.573
Interfaces
N32-c / N32-f (Inter-PLMN Roaming)Nsepp
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