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Transcript of Seamless & Secure Mobility Nada Golmie Advanced Networking Technologies Division National Institute...
Seamless & Secure Mobility
Nada Golmie
Advanced Networking Technologies Division
National Institute of Standards and Technologies
Gaithersburg, MD 20899
USA
www.antd.nist.gov
2
Seamless Future Networks
IP Based Core Networks
Media Access Systems
Services and Applications
Short RangeConnectivity
cellular
WirelineDSL/modem
WLAN
Interworking
Mobility Management
Roaming
Network of Networks
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Everyday Usage Scenarios
Internet
EthernetWi-Fi
Cellular
Wi-Fi
Wi-Max
In the office
In the car
Out of Town
Wi-Fi
Wi-Fi
Wi-Fi
AP1AP2
AP3
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Mobility Granularity
Horizontal Handover
Vertical Handover
Multiple Interface Management
Multiple Flow Management
A handover is initiated when mobile device exits the boundaries of an administrative domain. Single interface is used.
A mobile device does need to move in order to initiate a handover. Multiple interfaces are required, but use one interface at a time.
Simultaneous use of multiple interfaces and access networks. Association of an application with an interface
Ability to split individual flows between links with respect to the requirements of the flows and the user preferences
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Key Challenges Scalability – roaming from any access network to any other
access network (2G, 3G, 4G, Wi-Fi, Wi-Max, Bluetooth, Satellite, Ethernet)
Standard handover interfaces – interoperability between different vendor equipment.
Cross-layer solutions - extensions to layer 1 & layer 2 functionalities in order to optimize higher layer mobility architectures (MIPv4, MIPv6, SIP).
QOS guarantees during handover – no disruption to user traffic: extreme low latency, signaling messages overhead and processing time, resources and routes setup delay, near-zero handover failures and packet loss rate
Security – user maintains the same level of security when roaming across different access networks.
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Access Scalability
Wide variety of access network technologies including cellular (2G, 2.5G, 3G), wireless (Wi-Fi, Wi-Max, Bluetooth, UWB) and wired (DSL, cable modems, Ethernet)
Data Rate (Mb/s)
IEEE 802.16a
Co
vera
ge
Are
a &
Mo
bil
ity
IEEE 802.11n
IEEE 802.15.1Bluetooth
IEEE 802.15.3a
Local Area
IEEE 802.15.4Zigbee
Metro Area802.3 Ethernet
10 base-T1000 base-T100 base-T
IEEE 802.20
IEEE 802.11a
IEEE 802.15.3
IEEE 802.11g
Personal Area
IEEE 802.11b
0.01 0.1 1 10 100 1000
Wide Area
High Speed Vehicular
Rural
Vehicular
Urban
Pedestrian
Indoor
Fixed Urban
Personal Area
2GGSM, CDMA
2.5GGPRS
3GCDMA2000, UMTS
DSL
Cable Modem
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Access Media Properties
Different media and coverage areas from few square meters to hundred of kilometers
Different architectures and protocols for routing, transport, mobility management
Different authentication, key management and encryption schemes
Different services offered and user demands ranging from low-data-rate non-real-time applications, to high-speed real-time multimedia applications.
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Industry and Standards Activities
UMA TechnologySession Initiation Protocol
IP Multimedia SubsystemInternet Engineering Task Force Detecting Network Attachment
Processing Layer 2 Triggers Mip4
Mobile IP version 6 Mip6
Mobile IP version 4 Mipshop
MIPv6 signaling and Handoff Optimization Mobopts
IP Mobility optimizations research group Nemo
Network Mobility
Higher Layers
No single standard interface!
IEEE 802
IEEE 802.21 Media Independent Handovers
IEEE 802.11rIEEE 802.11 Fast handovers
IEEE 802.11uInterworking with external networks
IEEE 802.20Mobile broadband wireless access
Layer 2
Layer 3
FMCA NOKIA
KT
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Cross-Layer Protocol Interactions
Profile Manager
AccessMedia
Applications
Policy
Mobility Decision
Cellular
PHY
MAC
Link measurements: RSSI, Noise, Interference
Performance Measure.:QOS, ACK
Handover Layer
Network Layer Mobile IP
trig
ger
trig
ger
trig
ger Transport Layer
SCTP
Application Layer SIP
trig
ger
trig
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trig
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Han
dove
r su
ppor
tWhat are the mobility architectures considered?
What are the protocols and messages needed?
What measurements will be used in the handover decision?
What are the mobility scenarios envisaged?
How can mobility performance be evaluated?
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Secure Mobility
Level 1
Level 2
Access Net. 1
Level 3
What additional encryption mechanisms and policies should be applied for secure access network transitions?
How to characterize security levels?
Level 2
Level 3
Level 1
Level 2
Level 3
Access Net. 2
Access Net. 3
Eg. GSM
Eg. Wi-Fi Eg. Wi-Max
Encryption + AuthenticationIntegrity Checking
ConfidentialityNon-RepudiationAuthenticationAuthorization
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•CCM-Mode 128 bit AES data encryption •CCM-Mode 128 bit AES data authentication•ECB mode AES, 128-bit key TEK encryption
•CBC-Mode 56-bit DES data encryption •no data authentication•RSA, 1024 TEK encryption
Comparing Cryptographic Suites
•CBC-Mode 56-bit DES data encryption •no data authentication•3-DES,128 TEK encryption
•No data encryption•no data authentication•RSA, 1024 TEK encryption
•No data encryption, •no data authentication•3-DES,128-bit TEK encryptionWhat are
possiblemappings?
IEEE 802.16
Security offered by different access network technologies does not compare.
CCMP data encryption802.1X authentication802.1X key management
IEEE 802.11
WRAP data encryption802.1X authentication802.1X key management
TKIP data encryption802.1X authentication802.1X key management
WEP-104 data encryption802.1X authentication802.1X key management
WEP data encryption802.1X authentication802.1X key management
CCMP data encryption802.1X authenticationNo key management
WRAP data encryption802.1X authenticationNo key management
TKIP data encryption802.1X authenticationNo key management
WEP-104 data encryption802.1X authenticationNo key management
WEP data encryption802.1X authenticationNo key management
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Factors Impacting Security
1. Radio Transmission
2. Network Architecture Cellular Mesh
3. Internetworking
4. Shared Medium CSMA/CA Polling
5. Cryptography
6. Mobility
7. Changing Network Topology
8. Limited Energy resources
9. Node Association
10. Power Save Mode
11. Logical channel sensing
12. Retransmission
13. Fragmentation
14. Threat Environment
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Practical Issues in Secure Mobility
Single administrative domain – pairing of user security levels on different access networks
Multiple administrative domain – need for (re)authentication
Lack of quantitative measures for security performance
Menu driven security options for equipment vendors and service providers increase complexity
Dependence on threat environment, equipment capabilities and usage scenarios.
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Project Roadmap
Tool Development Protocol Analysis Protocol Development
DeliverablesWhy NIST?
Technology GapLack of measurement tools OpportunityLack of standards
Industry Standards Sponsors
• Plug-and-play simulations- Choice of platform- Extensions- Abstractions• Analytical models• Performance Metrics• Usage Scenarios
IEEE 802 > development of standard interfacesIETF > lower layer meas.
Engage potential customersDetermine need/requirementsAdvertise program
Information Assurance Workshop, Feb. 2005
• Quantify handover performance in terms of latency, loss, signaling, security• Identify protocol cross-layer interactions• Explore and map lower layer measurements• Devise service/ security profiles mappings
• Mobility architecture• Decision algorithms and optimizations• Extensions to existing protocols• Policy Mapping
Start
• Mobility tool & measurement repository• Publication of comparative performance analysis results• User guidelines• Best practices• Contributions to Industry standard developments
Competence
Impact
Strategic
Technical
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An Approach to Secure Mobility
Transitional Security Security Levels Mappings
Sin
gle
Adm
in.
Dom
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Mul
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dmin
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Vulnerability analysis:- Are there any additionalthreats and weaknessesposed by the mobility?handover?- What are they?-Under what threat models?- How to mitigate them?
1) Select two technologies as a starting point: for example 802.11b and 802.162) Assess vulnerabilities associated with handover scenarios and related threat models3) Identify security levels or tiers based on weakness analysis available for each
technology4) Devise security level mappings between different technologies5) Extend the analysis to the multi-administrative domain case
Identify levels of security based on protocol description and weakness analysis:-How to map comparable levels of security?-What additional security policies and mechanisms need to be applied in order to maintain the same level of security (or vulnerability)?
Extensions of vulnerability analysis:-Investigate scenario andapplication specific cases- Devise taxonomy
Extensions of security levels: - what are the security policies required for specific mobility and application scenarios?
Start
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Deliverables arein the form:•Mobility securityrequirements•Security levels andmappings•User Guidelines
•Lessons learned•Limits of technology•Feasibility study
Secure & Seamless Mobility
Action Plan• Develop plug-and-play mobility simulation platform:
- Assess state of the art & availability of tools available in the public domain.
- Build model extensions and abstractions to accurately characterize protocol interactions
• Derive analytical models for evaluating handover latency, and transition blocking probability.
• Devise benchmarks and realistic usage scenarios.
• Devise metrics for quantifying handover performance.
• Devise and evaluate handover protocol optimizations and decision algorithms.
• Devise access link security profiles and mappings across access link technologies.
Technical Approach
Investigate mobility protocols and methods that characterize & improve their performance.Bridging the interconnection gap between heterogeneous
and “stovepipe” access network technologies
Deliverables• Contribute to standard group activities such as
IETF and IEEE 802: conduct comparative performance evaluation of handover mechanisms being considered in IEEE 802
• Create and maintain a repository of tools, benchmarks and performance metrics on NST Web site.
• Publish performance analysis results in conference / journal articles: characterize implications on handover performance including mobility management, QOS, and security.
Key Questions
How to support seamless mobility across different access network technologies?
How to maintain security when handing over a connection from one access link to another access link?
Internet