1. 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. 2
Outline
Origin of the ITU-T Recommendation X.805 - 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. 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.509 -
Public-key and Attribute Certificate Frameworks.
4. 4
Three main issues that X.805
addresses
The security architecture addresses three essential
issues:
1. What kind of protection is needed and against what
threats?
2. What are the distinct types of network equipment and
facility groupings that need to be protected?
3. What are the distinct types of network activities that
need to be protected?
5. 5
ITU-T X.800 Threat Model
(simplified)
X
X
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
6. 6
Access Control
Authentication
Non-repudiation
Data Confidentiality
Communication Security
Data Integrity
Availability
Privacy
• Limit & control access to
network elements, services &
applications
• Examples: password, ACL,
firewall
• Prevent ability to deny that an
activity on the network
occurred
• Examples: system logs,
digital signatures
• Ensure information only flows
from source to destination
• Examples: VPN, MPLS,
L2TP
• Ensure network elements,
services and application
available to legitimate users
• Examples: IDS/IPS, network
redundancy, BC/DR
• Provide Proof of Identity
• Examples: shared secret,
PKI, digital signature, digital
certificate
• Ensure confidentiality of data
• Example: encryption
• Ensure data is received as
sent or retrieved as stored
• Examples: MD5, digital
signature, anti-virus software
• Ensure identification and
network use is kept private
• Examples: NAT, encryption
Eight Security Dimensions Address
the Breadth of Network Vulnerabilities
Eight Security Dimensions applied to each Security Perspective (layer and plane)
7. 7
How the Security Dimensions
Map to the Security Threats
Security
Dimension
X.800 Security Threats
Destruction Corruption Removal Disclosure Interruption
Access Control
Authentication
Non-Repudiation
Data Confidentiality
Communication
Security
Data Integrity
Availability
Privacy
8. 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. 9
Three Security Layers
• Each Security Layer has unique vulnerabilities, threats
• Infrastructure security enables services security enables applications security
Infrastructure Security
Applications Security
Services Security
THREATS
VULNERABILITIES
ATTACKS
Destruction
Disclosure
Corruption
Removal
Infrastructure Security
Applications Security
Services Security
VULNERABILITIES
Interruption
Vulnerabilities Can Exist
In Each Layer
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
3 - Applications Security Layer:
• Network-based applications accessed by
end-users
• Examples:
– Web browsing
– Directory assistance
– Email
– E-commerce
10. 10
Example: Applying Security Layers to
IP Networks
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., email)
– High-end applications (e.g., e-commerce, e-training)
11. 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. 12
• 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
Three Security Planes
Infrastructure Security
Applications Security
Services Security
End User Security
Control/Signaling Security
Management Security
VULNERABILITIES
Security Layers
Security Planes
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., email)
2 - Control/Signaling Security Plane:
• Activities that enable efficient functioning of
the network
• Machine-to-machine communications
3 - Management Security Plane:
• The management and provisioning of
network elements, services and applications
• Support of the FCAPS functions
14. 14
Access
Management
Infrastructure Security
Applications Security
Services Security
End User Security
Control/Signaling Security
Management Security
8 Security Dimensions
Data
Confidentiality
Communication
Security
Integrity
Availability
Privacy
Authentication
Non-repudiation
Security Layers
Security Planes Access
Control
Infrastructure Security
Applications Security
Services Security
End User Security
Control/Signaling Security
Management Security
THREATS
VULNERABILITIES
8 Security Dimensions
ATTACKS
Data
Confidentiality
Communication
Security
Data
Integrity
Availability
Privacy
Authentication
Non-repudiation
Security Layers
Security Planes
ITU-T X.805: Security Architecture for Systems
Providing End-to-End Communications
Vulnerabilities
Can Exist
In Each
Layer,
Plane
Destruction
Disclosure
Corruption
Removal
Interruption
15. 15
– Management Network: top row
– Network Services: middle column
– Security Module: Layer & Plane
Intersection
Access Control
Authentication
Non-repudiation
Data Confidentiality
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
Communication Security
Data Integrity
Availability
Privacy
The eight Security Dimensions Are
Applied to Each Security Module
Modular Form of X.805
Provides a systematic, organized way for performing network security
assessments and planning
16. 16
Module 3 – Infrastructure Layer – End-
User Plane
www.lucent.com/security
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. 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. 18
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. 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
