1. ITU-T Recommendation X
ITU-T Recommendation X.805 Security Architecture for Systems Providing End-to-End Communications
IETF 63 meeting
Zachary Zeltsan,
Bell Laboratories,
Lucent Technologies
Rapporteur of Question 5 SG 17

2. Outline
Origin of the ITU-T Recommendation X Security Architecture for Systems Providing End-to-End Communications
Three main issues that X.805 addresses
Security Dimensions
Security Layers
Security Planes
ITU-T X.805 Security Architecture
ITU-T Recommendation X.805 as a base for security work in FGNGN Security Capability WG

3. Origin of the ITU-T Recommendation X.805
ITU-T Recommendation X.805 Security architecture for systems providing end‑to‑end communications had been developed by ITU-T SG 17 (ITU-T Lead Study Group on Telecommunication Security) and was published in October 2003.
The group has developed a set of the well-recognized Recommendations on security. Among them are X.800 Series of Recommendations on security and X Public-key and Attribute Certificate Frameworks.

4. Three main issues that X.805 addresses
The security architecture addresses three essential issues:
What kind of protection is needed and against what threats?
What are the distinct types of network equipment and facility groupings that need to be protected?
What are the distinct types of network activities that need to be protected?

5. ITU-T X.800 Threat Model (simplified)
1 - Destruction (an attack on availability):
Destruction of information and/or network resources
2 - Corruption (an attack on integrity):
Unauthorized tampering with an asset
3 - Removal (an attack on availability):
Theft, removal or loss of information and/or other resources
4 - Disclosure (an attack on confidentiality):
Unauthorized access to an asset
5 - Interruption (an attack on availability):
Interruption of services. Network becomes unavailable or unusable X X

6. Communication Security
Eight Security Dimensions Address the Breadth of Network Vulnerabilities
Limit & control access to network elements, services & applications
Examples: password, ACL, firewall
Access Control
Provide Proof of Identity
Examples: shared secret, PKI, digital signature, digital certificate
Authentication
Prevent ability to deny that an activity on the network occurred
Examples: system logs, digital signatures
Non-repudiation
Ensure confidentiality of data
Example: encryption
Data Confidentiality
Ensure data is received as sent or retrieved as stored
Examples: MD5, digital signature, anti-virus software
Communication Security
Ensure information only flows from source to destination
Examples: VPN, MPLS, L2TP
Data Integrity
Availability
Ensure network elements, services and application available to legitimate users
Examples: IDS/IPS, network redundancy, BC/DR
Ensure identification and network use is kept private
Examples: NAT, encryption
Privacy
Eight Security Dimensions applied to each Security Perspective (layer and plane)

7. How the Security Dimensions Map to the Security Threats
X.800 Security Threats
Destruction
Corruption
Removal
Disclosure
Interruption
Access Control 
Authentication
Non-Repudiation
Data Confidentiality
Communication Security
Data Integrity
Availability
Privacy

8. Security Layers
Concept of Security Layers represents hierarchical approach to securing a network
Mapping of the network equipment and facility groupings to Security Layers could be instrumental for determining how the network elements in upper layers can rely on protection that the lower layers provide.

9. Vulnerabilities Can Exist
Three Security Layers
Infrastructure Security
Applications Security
Services Security
THREATS
VULNERABILITIES
ATTACKS
Destruction
Disclosure
Corruption
Removal
Interruption
Vulnerabilities Can Exist
In Each Layer
3 - Applications Security Layer:
Network-based applications accessed by end-users
Examples:
Web browsing
Directory assistance
E-commerce
1 - Infrastructure Security Layer:
Fundamental building blocks of networks services and applications
Examples:
Individual routers, switches, servers
Point-to-point WAN links
Ethernet links
2 - Services Security Layer:
Services Provided to End-Users
Examples:
Frame Relay, ATM, IP
Cellular, Wi-Fi,
VoIP, QoS, IM, Location services
Toll free call services
Each Security Layer has unique vulnerabilities, threats
Infrastructure security enables services security enables applications security

10. Example: Applying Security Layers to IP Networks
Infrastructure Security Layer
Individual routers, servers
Communication links
Services Security Layer
Basic IP transport
IP support services (e.g., AAA, DNS, DHCP)
Value-added services: (e.g., VPN, VoIP, QoS)
Applications Security Layer
Basic applications (e.g. FTP, web access)
Fundamental applications (e.g., )
High-end applications (e.g., e-commerce, e-training)

11. Security Planes
Concept of Security Planes could be instrumental for ensuring that essential network activities are protected independently (e.g. compromise of security at the End-user Security Plane does not affect functions associated with the Management Security Plane).
Concept of Security Planes allows to identify potential network vulnerabilities that may occur when distinct network activities depend on the same security measures for protection.

12. Three Security Planes 1 - End-User Security Plane:
Infrastructure Security
Applications Security
Services Security
End User Security
Control/Signaling Security
Management Security
VULNERABILITIES
Security Layers
Security Planes
Vulnerabilities Can Exist
In Each Layer and Plane
THREATS
ATTACKS
Destruction
Disclosure
Corruption
Removal
Interruption
1 - End-User Security Plane:
Access and use of the network by the customers for various purposes:
Basic connectivity/transport
Value-added services (VPN, VoIP, etc.)
Access to network-based applications (e.g., )
3 - Management Security Plane:
The management and provisioning of network elements, services and applications
Support of the FCAPS functions
2 - Control/Signaling Security Plane:
Activities that enable efficient functioning of the network
Machine-to-machine communications
Security Planes represent the types of activities that occur on a network.
Each Security Plane is applied to every Security Layer to yield nine security Perspectives (3 x 3)
Each security perspective has unique vulnerabilities and threats

13. Example: Applying Security Planes to Network Protocols
End User Security Plane
Activities
End-user data transfer
End-user – application interactions
Protocols
HTTP, RTP, POP, IMAP
TCP, UDP, FTP
IPsec, TLS
Control/Signaling Security Plane
Activities
Update of routing/switching tables
Service initiation, control, and teardown
Application control
Protocols
BGP, OSPF, IS-IS, RIP, PIM
SIP, RSVP, H.323, SS7.
IKE, ICMP
PKI, DNS, DHCP, SMTP
Management Security Plane
Operations
Administration
Management
Provisioning
Activities
Protocols
SNMP
Telnet
FTP
HTTP

14. ITU-T X.805: Security Architecture for Systems Providing End-to-End Communications
Security Layers
Security Layers
THREATS
Applications Security
Applications Security
Destruction
Disclosure
Corruption
Removal
Interruption
VULNERABILITIES
Services Security
Services Security
repudiation
repudiation
Data Integrity
Access Management
Authentication
Authentication
Data Confidentiality
Data Confidentiality
Communication Security
Communication Security
Integrity
Availability
Availability
Privacy
Privacy
Access Control
Vulnerabilities Can Exist
In Each
Layer,
Plane - -
Non
Non
ATTACKS
Infrastructure Security
Infrastructure Security
End User Security
End User Security
Security Planes
Security Planes
Control/Signaling Security
Control/Signaling Security
8 Security Dimensions
8 Security Dimensions
Management Security
Management Security

15. The eight Security Dimensions Are Applied to Each Security Module
Modular Form of X.805
Infrastructure Layer
Services Layer
Applications Layer
Management Plane
Module one
Module four
Module seven
Control/Signaling Plane
Module two
Module five
Module eight
User Plane
Module three
Module six
Module Nine
Access Control
Communication Security
Management Network: top row
Network Services: middle column
Security Module: Layer & Plane Intersection
Authentication
Data Integrity
Non-repudiation
Availability
Data Confidentiality
Privacy
The eight Security Dimensions Are Applied to Each Security Module
Provides a systematic, organized way for performing network security assessments and planning

16. Module 3 – Infrastructure Layer – End-User Plane
Security Dimension
Security Objectives
Access Control
Ensure that only authorised personnel or devices are allowed access to end-user data that is transiting a network element or communications link or is resident in an offline storage device.
Authentication
Verify the identity of the person or device attempting to access end-user data that is transiting a network element of communications link or is resident in an offline storage device.
Authentication techniques may be required as part of Access Control.
Non-Repudiation
Provide a record identifying each individual or device that accessed end-user data that is transiting a network element or communications link, or is resident in offline devices and that the action was performed. The record is to be used as proof of access to end-user data.
Data Confidentiality
Protect end-user data that is transiting a network element or communications link, or is resident in an offline storage device against unauthorised access or viewing. Techniques used to address access control may contribute to providing data confidentiality for end-user data.
Communication Security
Ensure that end-user data that is transiting a network element or communications link is not diverted or intercepted as it flows between the end points (without an authorised access)
Data Integrity
Protect end-user data that is transiting a network element or communications link or is resident in offline storage devices against unauthorised modification, deletion, creation and replication.
Availability
Ensure that access to end-user data resident in in offline storage devices by authorised personnel and devices cannot be denied.
Privacy
Ensure that network elements do not provide information pertaining to the end-users network activities (eg. Users geographic location, websites visited, content etc.) to unauthorised personnel.

17. Summary: X.805 Provides a Holistic Approach to Network Security
Comprehensive, end-to-end network view of security
Applies to any network technology
Wireless, wireline, optical networks
Voice, data, video, converged networks
Applies to variety of networks
Service provider networks
Enterprise (service provider’s customer) networks
Government networks
Management/operations, administrative networks
Data center networks
Is aligned with other security ITU-T Recommendations and ISO standards

18. NGN security requirements for Release 1 and X.805
ITU-T Recommendation X.805 is a Base for Security work in FGNGN Security Capability WG
Guidelines for NGN security and X.805
NGN threat model (based on ITU-T X.800 and X.805 Recommendations)
Security Dimensions and Mechanisms (based on ITU-T X.805)
Access control
Authentication
Non-repudiation
Data confidentiality
Communication security
Data integrity
Availability
Privacy
NGN security requirements for Release 1 and X.805
General considerations based on the concepts of X.805

19. Acronyms AAA Authentication, Authorization, Accounting
ACL Access Control List
ATM Asynchronous Transfer Mod
BC Business Continuity
BGP Border Gateway Protocol
DHCP Dynamic Host Configuration Protocol
DNS Domain Name Service
DR Disaster Recovery
FCAPS Fault-management, Configuration, Accounting, Performance, and Security
FTP File Transfer Protocol
HTTP Hyper Text Transfer Protocol
ICMP Internet Control Message Protocol
IDS Intrusion Detection System
IKE Internet Key Exchange protocol
IM Instant Messaging
IMAP Internet Message Access Protocol
IPS Intrusion Prevention System
IPsec IP security (set of protocols)
IS-IS Intermediate System-to-Intermediate System (routing protocol)
L2TP Layer Two Tunneling Protocol
MPLS Multi-Protocol Label Switching
NAT Network Address Translation
OSPF Open Shortest Path First
PIM Protocol-Independent Multicast
PKI Public Key Infrastructure
POP Post Office Protocol
QoS Quality of Service
RIP Routing Information Protocol
RSVP Resource Reservation Setup Protocol
RTP Real-time Transport Protocol
SIP Session Initiation Protocol
SMTP Simple Mail Transfer Protocol
SNMP Simple Network Management Protocol
SS7 Signaling System 7
TCP Transmission Control Protocol
TLS Transport Layer Security protocol
UDP User Datagram Protocol
VoIP Voice over IP
VPN Virtual Private Network

20. Thank you!