Security in Mobile and Wireless Networks Security Issues in - apricot

131 Pages·2006·5.05 MB·English

Security in Mobile and Wireless
Networks
APRICOT Tutorial
Perth Australia
27 February, 2006
Ray Hunt, Associate Professor
Dept. of Computer Science and Software Engineering
University of Canterbury, New Zealand
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Security Issues in Wireless and
Mobile IP Networks
Section 1 - Wireless & Mobile IP
Architecture, Standards, (Inter)operability,
Developments
Section 2 - Cryptographic Tools for Wireless
Network Security
Section 3 - Security Architectures and
Protocols in Wireless LANs
Section 4 - Security Architectures and
Protocols in 3G Mobile Networks
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1
Wireless & Mobile IP
Architecture, Standards,
(Inter)operability,
Developments
(Section 1)
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Outline
Wireless LANs – Standards, Architecture
 IP roaming
 Wireless security and authentication
 QoS (Quality of Service)
 Integration of 3G and WLANs
 New Developments by IEEE - Broadband
Wireless Access
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2
Wireless IP Networking Revolution
Past Present Future
Paradigms Demand Solutions
Local Area
WLAN
- On campus
Unlicensed Bands
Fixed - At home
Data • Personal mobility
Mobility Combined
• High data rate
with • Incremental infrastructure
“handoff”
Network
Connectivity
(Data + Voice) “3G” WCDMA Wide Area
Mobile Licensed Bands - On the road
Voice
• Full mobility
• Modest data rate
• All new infrastructure
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Recent WLAN Activity ….
IEEE and ETSI involved in standardisation

WLAN standards are converging to

achieve interoperability
Integration of WLAN and 3G appearing

Wireless IP momentum - rapid growth in

requirements for mobile IP access
WLAN offers good mobile solution for

indoor IP access
Major players investing in WLAN (CISCO,

Intel, Ericsson, Nokia, others …)
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3
WLAN Architecture
Standards, MAC Layer,
Frequency Spectrum,
Speed/Distance
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Standards Organisation in IEEE
IEEE Standards Association
Standards Activities Board
Sponsor Sponsor Sponsor
Local and Metropolitan Area Networks
(LMSC, IEEE 802)
802.3 802.11 802.15 802.16
802.5
CSMA/CD CSMA/CA Wireless Broadband
Token Passing
Ethernet Wireless Personal Wireless
Ring
1-100 Mbps WLAN Area Networks Broadband Access
IEEE 802.11: ~650 Members, 250+

supporting companies
www.ieee802.org/11

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4
WLAN Standards Evolution
2.4 GHz (BW 80 MHz) 5 GHz (BW 450 MHz)
ETSI BRAN
Proxim OpenAir FH
1996 1.6 Mbps HyperLAN/1
24 Mbps
1997 IEEE 802.11 FH IEEE 802.11 DS
1, 2 Mbps 1, 2 Mbps
1998
IEEE802.11a
1999 HomeRF FH IEIEEEE E80 820.121.1b1 HbR OFDM
1.6 Mbps 11,, 22,, 55..55,, 1111 MMbbppss
Replaced by 54 Mbps
IEEE 802.15
P2A0N0s0 -(52004) IEExtEeEns 8io0n2s.11 EETTSSII BBRRAANN
eg Bluetooth 802.11g (54 Mbps) HHyippeerrLLAANN//22
802.11a (54 Mbps) 5544 MMbbppss
Under
Development IEEE 802.16a/e
IEEE 802.20 9
2006 Broadband Access
ISO Model Applied to WLANs
Application
LLC provides traditional HDLC type
protocol
Presentation
MAC controls access to the physical
Session channel according to a predetermined
set of rules
Transport
Network
Logical Link Control
(LLC) Main differences:
Datalink • Radio link unreliable
Medium • Higher error rate
Access Control (MAC) • Security risks
Physical
• All traffic goes via
AP (Access Point)
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5
MAC Overview
IP Packets
MAC Layer Management Entity (MLME) MAC DSAP
• Retransmission,
error correction
radio mgmt association Fragmentation
e.g. scanning management & ARQ
power shared-key WEP (RC4) & AES
management authentication encryption
• Radio link security
• Data authentication
• Data encryption
management
addressing framing • Simple scrambling
info base (MIB)
• Peer-to-peer
• 48 bit MAC address
CSMA/CA
• Ethernet compliant channel access
• Unique identifier
• Radio link QoS
• Multicast and
• Dedicated real-time
broadcast support PHY SAP support with 802.11e
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Key Wireless LAN Technologies
Older technologies limited speed to 1-2 Mbps
Significant developments by IEEE 802.11
Variety of standards  speeds up to 54 Mbps
IEEE 802.11a/b/g (11 & 54 Mbps) - popular
To compete with traditional LANs, wireless
must offer:
cost effect solutions
security
efficient power management
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6
Key Wireless LAN Technologies
 IEEE 802.11b (11 Mbps) 2.4 GHz (Wi-Fi)
 IEEE 802.11a (54 Mbps) 5 GHz (Wi-Fi5)
 IEEE 802.11g (54 Mbps) 2.4 GHz
 IEEE 802.16 / 802.20 Broadband Wireless Access
Standard (Wireless MANs)
 Bluetooth Wireless PAN (Personal Area Network)
2.4 GHz (= IEEE 802.15) www.bluetooth.com
 HomeRF (1.6 Mbps) 2.4 GHz www.homerf.org
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Courtesy UMTS Forum
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WLANs: Speed/Distance Scenarios
Wireless
54 Mbps
Multimedia
+ 802.11a 802.16
802.11g 802.20
IEEE 802.11b
dominates in products
11 Mbps 802.11b
Wireless Local
Area Coverage
5,5 Mbps
2 Mbps
802.11
1 Mbps 3G WANs
500 Kbps
10m 30m 60m 100m 200m > 400m
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IEEE 802.11 Standards contd ...
ATM Speed IEEE 802.11g Ethernet Speed
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8
“Actual” Realistic Speeds
MAC / PHY overhead Higher rate & PER -> lower throughput
PER: Packet Error Rate
Courtesy of Atheros 17
IEEE 802.11a/b/g
 IEEE 802.11 Working Group provided
extensions to 802.11b for data rates above 20
Mbps leading to IEEE 802.11g
IEEE 802.11g offers 802.11a data rates in 2.4
GHz band and requires mandatory
implementation of IEEE 802.11b modes
This standard provides a path for development
of multi-mode WLAN products
IEEE 802.11a  IEEE 802.11g  IEEE 802.11b
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9
Summary of Key Differences
Standard Distance (m) Speed (Mbps) Power (mw)
IEEE802.11b <100 11 (~6) 50-100
IEEE802.11g <100 54 (~30) 50-100
IEEE802.11a <50 55 (~30) 200
Bluetooth 10-100 1 1 (10m)
100 (100m)
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Additional Requirements …..
IP Mobility between WLAN subnets and into
3G networks
Authentication - local and remote
Security across the airwaves, end-to-end,
Wireless LAN, Wireless WAN (3G)
Quality of Service - to support time dependant
applications
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