Regulations describe risk management and evidence.
Audit frameworks describe processes and controls.
Attackers care about protocol behavior.
This is why 3GPP and GSMA security specifications quietly define the real security standard for mobile networks. They describe how authentication works, how keys are protected, how roaming traffic should be filtered and how network equipment must behave under stress.
When regulators or auditors ask whether a network is aligned with international best practice, these are the documents they implicitly rely on.
The role of 3GPP in defining mobile network security
3GPP develops the normative security architecture for mobile systems. The bulk of this work is produced in the 33 series of specifications, which define the security model from 3G to 5G.
For operators, three document families matter most.
3G security architecture
This set of specifications describes confidentiality, integrity and authentication mechanisms for third generation mobile systems. It defines how user identity is protected, how encryption keys are derived and how the network authenticates subscribers.
LTE security architecture
The LTE security architecture introduces NAS and AS protection, key hierarchy definitions and requirements for securing signaling between core network functions. It also prescribes security behavior for mobility management, authentication, and network domain protection.
5G security architecture
The 5G security model expands protection to the service based architecture. It introduces enhanced subscriber privacy, stricter roaming requirements, protection of network APIs, and updated key hierarchies. It also defines expectations for mutual authentication between network functions.
Beyond these architectural definitions, 3GPP publishes Security Assurance Specifications that define technical security and test requirements for individual network functions such as AMF, SMF, gNB and others. These documents form the basis for product evaluation and technical audits.
3GPP answers three essential questions for operators
What must be protected in every generation of mobile network
Which cryptographic algorithms and key hierarchies are acceptable
How network functions should authenticate and protect signaling
GSMA fraud and security guidelines
If 3GPP defines the architecture, GSMA defines how it should behave operationally.
GSMA’s Fraud and Security Group maintains guidelines that translate 3GPP theory into practical defensive expectations, especially in roaming and interconnect environments.
Several document families form the real-world baseline for operator security teams.
SS7 interconnect security
GSMA provides detailed security controls for SS7 networks, including
Filtering rules for MAP, CAP and SCCP
Detection of malicious traffic patterns
Recommended logging and monitoring practices
Expected behavior for interconnect firewalls
These guidelines define the minimum requirements for securing 2G and 3G signaling in roaming and national interconnect scenarios.
Diameter and GTP security for LTE and 5G
For LTE and 5G, GSMA security profiles cover
Filtering recommendations for Diameter S6a, S6d, S9, and Gx
Mitigation techniques for mobility and authentication fraud attempts
Correlation rules between Diameter messages
Threat modeling for GTP-C signaling used to create user plane tunnels
Operators rely on these guidelines to configure signaling firewalls, validate roaming partner behavior and protect their core from malformed or hostile traffic.
Roaming and backbone security
GSMA also maintains documents governing secure behavior on GRX and IPX networks, including DNS, ENUM, routing, and encryption requirements.
These serve as baseline expectations when establishing or auditing roaming agreements.
GSMA guidelines answer questions such as
Which signaling messages must be blocked outright
Which partner behaviors indicate compromise or abuse
What capabilities a signaling protection platform must support
How roaming partners should exchange security alerts
NESAS and SCAS bridging standards and equipment assurance
NESAS is the joint 3GPP and GSMA security assurance framework for validating network equipment. It provides
Process assurance
Audits of vendor development processes, patching policy and vulnerability management
Technical testing
Independent lab testing of network functions against detailed 3GPP Security Assurance Specifications
Common security vocabulary
A shared baseline that procurement, regulators and operators can use to evaluate equipment consistently
NESAS does not replace penetration testing or continuous monitoring, but it creates a unified expectation for network equipment hardening, especially in 5G deployments.
Why regulators implicitly rely on these documents
Telecom-specific regulations rarely list protocol-level requirements. Instead, they focus on outcomes such as
Risk assessment
Monitoring and logging
Incident response
Vendor assurance
Evidence-based controls
In practice, regulators rely on 3GPP and GSMA security documents as the technical foundation for these outcomes.
For example
Expectations for interconnect security map directly to GSMA’s SS7, Diameter and GTP guidance
Vendor assurance expectations are mapped to NESAS and SCAS coverage
Cryptographic and authentication requirements rely on 3GPP’s security architecture definitions
A compliance strategy that does not include these standards may meet policy requirements on paper but will not hold up during audits or incidents.
Practical checklist for operators
Here is a concise approach operators can use to align with 3GPP and GSMA security specifications.
- Map regulations to technical standards
Link each regulatory requirement to one or more 3GPP or GSMA documents.
For example
Core network security aligns with the 3GPP 33 series
Interconnect filtering aligns with GSMA SS7, Diameter, and GTP guidelines
Vendor security aligns with NESAS and SCAS - Inventory your actual implementation
List which filtering categories, correlation rules and hardening requirements you have implemented across SS7, Diameter and GTP.
Identify dependencies on legacy behavior or exceptions. - Integrate NESAS data into your vendor strategy
Use NESAS and SCAS results to validate vendor maturity.
Identify gaps that require additional testing or hardening. - Validate real behavior with traffic
Many GSMA requirements are behavioral rather than theoretical.
Use traffic capture, replay and synthetic testing to confirm firewall and inspection logic. - Maintain a living gap register
Document gaps against 3GPP and GSMA expectations.
Track mitigation plans and progress.
Use this register as audit-ready evidence.
Conclusion
3GPP and GSMA security specifications define the technical standard for securing mobile networks.
3GPP provides the architecture for authentication, encryption, integrity and network function security from 3G to 5G.
GSMA translates these architectures into operational controls for roaming, interconnect, signaling filtering and fraud prevention.
NESAS and SCAS connect vendor development and equipment testing to these expectations.
For any operator working toward real regulatory alignment and real-world security, these specifications form the only baseline that matters.
