14-06-2012, 03:40 PM
Wireless Communications Security Issues, Solutions and Challenges
Security Requirements
Availability
no jamming, adaptability to unforeseen topologies
Privacy
nondisclosure of cell phone communications and 802.11 frames
Integrity
data is not intercepted and tampered
Legitimate participants
no cell phone cloning and 802.11 frame spoofing
Absence of misbehavior
fairness, greedy user detection
How to Deal With Jamming?
Increase the bandwidth
Frequency Hopping/Direct Sequence Spread Spectrum
801.11(b) : 2.4 - 2.4835 Giga Hertz
801.11(a): 5.15- 5.35 Giga Hertz; 5.725- 5.825 Giga Hertz
Ultra Wide Band
Bandwidth greater than 25% if center frequency
Increase the power
GPS III, planned for 2010 [Ashley, Next-Generation GPS, Scientific American, September 2003.]
Cellular Phone Eavesdropping
Inexpensive equipment for intercepting analog communications is easy to obtain in Canada.
In US, the regulations authorize the sale of scanners to the general public only is cellular frequencies are blocked. However, there are several workarounds
Web sites publish modifications to restore reception of cellular frequencies by scanners.
Frequency converters can translate cellular frequencies to the frequency range supported by a receiver.
With receivers using non quadrature mixing, the image frequency technique can be used.
Digital communications can also be intercepted with the appropriate equipment!
Generations of Cellular Mobile Radiophones
1G
Advanced Mobile Phone System (AMPS): 1980s, Frequency Modulation (FM), Frequency Division Multiple Access (FDMA), handover between cells, limited roaming between networks
2G
Global System for Mobile communications (GSM): 1990s, digital-coding of voice, Time Division Multiple Access (TDMA), Subscriber Identity Module (SIM), data communications
3G
3G Partnership Project (3GPP), Universal Mobile Telecommunications System (UMTS): 1998-, Wideband Code Division Multiple Access (WCDMA), use of GSM network model, global roaming; 2 Mbps data
4G
All-IP-based, 100 Mbps data
Challenge: Co-existence of analog technology and digital technology
The digital technology has higher potential for being secure than analog technology. For example, the Cellular Digital Packet Data (CDPD) uses data encryption and provides privacy.
Most of the cellular phones use hybrid technology, both analog and digital. The reason for that is that digital communications require a relatively stronger signal, for intelligibility, than analog communications, all other things being equal (such as bandwidth of a voice channel). A cell phone will hence operate in digital mode over relatively short distances.
In order to enable long range communications, cell phones fall back to the analog mode when the signal gets too weak for digital communications. As a result, digital systems inherit all the security vulnerabilities of analog systems.
Co-existence of legacy analog technology and digital technology is a challenge for system security design.
Radio Frequency Fingerprinting (RFF)
Background
Technique used by research teams including [H. Choe et al., 1995, Ureten 1999] for the purpose of identifying RF transceivers
Premise: a transceiver can be uniquely identified based on the characteristics of the transient section of the signal it generates
Primary benefit: Non-malleability of device identity
based on hardware characteristics of the transceiver
Key Objective:
Create a profile of the user’s device (transceiver) using RFF
Make use of both user and device profiles for authentication purposes
Wireless Network – device profile and MAC address
Cellular Network – device profile and IMSI
Security Requirements
Availability
no jamming, adaptability to unforeseen topologies
Privacy
nondisclosure of cell phone communications and 802.11 frames
Integrity
data is not intercepted and tampered
Legitimate participants
no cell phone cloning and 802.11 frame spoofing
Absence of misbehavior
fairness, greedy user detection
How to Deal With Jamming?
Increase the bandwidth
Frequency Hopping/Direct Sequence Spread Spectrum
801.11(b) : 2.4 - 2.4835 Giga Hertz
801.11(a): 5.15- 5.35 Giga Hertz; 5.725- 5.825 Giga Hertz
Ultra Wide Band
Bandwidth greater than 25% if center frequency
Increase the power
GPS III, planned for 2010 [Ashley, Next-Generation GPS, Scientific American, September 2003.]
Cellular Phone Eavesdropping
Inexpensive equipment for intercepting analog communications is easy to obtain in Canada.
In US, the regulations authorize the sale of scanners to the general public only is cellular frequencies are blocked. However, there are several workarounds
Web sites publish modifications to restore reception of cellular frequencies by scanners.
Frequency converters can translate cellular frequencies to the frequency range supported by a receiver.
With receivers using non quadrature mixing, the image frequency technique can be used.
Digital communications can also be intercepted with the appropriate equipment!
Generations of Cellular Mobile Radiophones
1G
Advanced Mobile Phone System (AMPS): 1980s, Frequency Modulation (FM), Frequency Division Multiple Access (FDMA), handover between cells, limited roaming between networks
2G
Global System for Mobile communications (GSM): 1990s, digital-coding of voice, Time Division Multiple Access (TDMA), Subscriber Identity Module (SIM), data communications
3G
3G Partnership Project (3GPP), Universal Mobile Telecommunications System (UMTS): 1998-, Wideband Code Division Multiple Access (WCDMA), use of GSM network model, global roaming; 2 Mbps data
4G
All-IP-based, 100 Mbps data
Challenge: Co-existence of analog technology and digital technology
The digital technology has higher potential for being secure than analog technology. For example, the Cellular Digital Packet Data (CDPD) uses data encryption and provides privacy.
Most of the cellular phones use hybrid technology, both analog and digital. The reason for that is that digital communications require a relatively stronger signal, for intelligibility, than analog communications, all other things being equal (such as bandwidth of a voice channel). A cell phone will hence operate in digital mode over relatively short distances.
In order to enable long range communications, cell phones fall back to the analog mode when the signal gets too weak for digital communications. As a result, digital systems inherit all the security vulnerabilities of analog systems.
Co-existence of legacy analog technology and digital technology is a challenge for system security design.
Radio Frequency Fingerprinting (RFF)
Background
Technique used by research teams including [H. Choe et al., 1995, Ureten 1999] for the purpose of identifying RF transceivers
Premise: a transceiver can be uniquely identified based on the characteristics of the transient section of the signal it generates
Primary benefit: Non-malleability of device identity
based on hardware characteristics of the transceiver
Key Objective:
Create a profile of the user’s device (transceiver) using RFF
Make use of both user and device profiles for authentication purposes
Wireless Network – device profile and MAC address
Cellular Network – device profile and IMSI