Telco Security

5G Security Architecture Guide

Comprehensive guide to securing next-generation mobile networks

5G Security Architecture Overview
Understanding the security foundations of 5G networks

Key Security Principles

Zero Trust Architecture

Never trust, always verify - continuous authentication and authorization

Defense in Depth

Multiple layers of security controls throughout the network

Network Slicing Isolation

Logical separation of network resources and traffic

Cloud-Native Security

Containerization, microservices, and API security

5G vs 4G Security Improvements

Enhanced Encryption

256-bit encryption vs 128-bit in 4G, mandatory user plane encryption

Subscriber Privacy

SUCI/SUPI mechanism prevents IMSI catching and subscriber tracking

Service-Based Architecture

API-based security with OAuth 2.0, TLS, and service mesh protection

Roaming Security

SEPP (Security Edge Protection Proxy) protects inter-operator communication

Architecture Components

5G Core (5GC)
Service-based architecture with network functions

Key Functions

AMF
SMF
UPF
AUSF
UDM
PCF
NSSF

Security Measures

  • Service mesh security
  • API gateway protection
  • Function isolation
Radio Access Network (RAN)
gNodeB and distributed units

Key Functions

CU
DU
RU
gNodeB

Security Measures

  • Air interface encryption
  • Integrity protection
  • Anti-jamming
Network Slicing
Logical network partitioning

Key Functions

eMBB
URLLC
mMTC

Security Measures

  • Slice isolation
  • Resource allocation
  • QoS enforcement
Edge Computing (MEC)
Distributed computing at network edge

Key Functions

Edge nodes
Application hosting
Local breakout

Security Measures

  • Edge security
  • Data locality
  • Access control

Security Features & Enhancements

Authentication
Improvement
Stronger than 4G AKA, prevents IMSI catching
  • 5G-AKA (Authentication and Key Agreement)
  • EAP-AKA' for non-3GPP access
  • Unified authentication framework
  • Subscription concealment (SUCI)
Encryption
Improvement
Stronger encryption than 4G, mandatory protection
  • 256-bit encryption algorithms
  • Mandatory encryption for user plane
  • Integrity protection for control plane
  • Algorithm negotiation security
Network Function Security
Improvement
API-based security, roaming protection
  • Service-based architecture (SBA)
  • OAuth 2.0 for NF authorization
  • TLS for NF communication
  • Security Edge Protection Proxy (SEPP)
Privacy
Improvement
Prevents subscriber tracking and IMSI catching
  • SUPI/SUCI mechanism
  • Home network public key encryption
  • Temporary identifiers
  • Location privacy enhancements

Deployment Models

Non-Standalone (NSA)
5G NR with 4G EPC core

Advantages

  • Faster deployment
  • Leverages existing 4G infrastructure
  • Lower initial cost

Disadvantages

  • Limited 5G features
  • Inherits 4G security limitations
  • No network slicing
Security Level
Moderate - inherits 4G vulnerabilities
Standalone (SA)
5G NR with 5G Core

Advantages

  • Full 5G features
  • Enhanced security
  • Network slicing support
  • Lower latency

Disadvantages

  • Higher deployment cost
  • Requires new infrastructure
  • Complex migration
Security Level
High - full 5G security features
Migration Strategy
Recommended path from 4G to 5G SA
1

Phase 1: NSA Deployment

Deploy 5G NR with existing 4G core for quick market entry

2

Phase 2: 5G Core Deployment

Build 5G core infrastructure in parallel with NSA operation

3

Phase 3: SA Migration

Gradually migrate subscribers to 5G SA for full feature access

4

Phase 4: 4G Decommissioning

Phase out 4G infrastructure as 5G SA coverage matures

Emerging Threats

Network Slicing Attacks
Cross-slice interference and resource exhaustion
High Impact

Mitigation Strategies

  • Strong slice isolation
  • Resource monitoring
  • Anomaly detection
API Security
Exploitation of service-based architecture APIs
Critical Impact

Mitigation Strategies

  • API gateway security
  • OAuth 2.0
  • Rate limiting
  • Input validation
Edge Computing Risks
Compromised edge nodes and data exposure
High Impact

Mitigation Strategies

  • Edge security hardening
  • Secure boot
  • Encrypted storage
  • Access control
Roaming Security
Inter-operator security vulnerabilities
High Impact

Mitigation Strategies

  • SEPP deployment
  • Roaming agreements
  • Traffic filtering
  • Monitoring