security challenges in wimax

8/3/2019 Security Challenges in WiMAX

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Security challenges in WiMAX

S. Yukesh Kumar

M. Neeraj Kumar


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Introduction

WiMAX, meaning Worldwide Interoperability for Microwave

Access, is a telecommunication technology that provides

wireless transmission of data .

WiMAX is wireless broadband technology, and a great alternative to

fixed broadband connections such as cable or DSL.

The technology is based on the IEEE 802.16 standard (also

called Broadband Wireless Access).


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WiMAX Tower

A single WiMAX tower can provide coverage to a very large area -- as big as

3,000 square miles (~8,000 square km).

A WiMAX tower station can connect directly to the Internet using a high-bandwidth, wired connection .

It can also connect to another WiMAX tower using a line-of-sight, microwave

link. This connection to a second tower (often referred to as a backhaul),

along with the ability of a single tower to cover up to 3,000 square miles, is

what allows WiMAX to provide coverage to remote rural areas.


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Types of Services Nonline-of-sight (NLOS)

Point to multipoint. (tower to individual connection)

Line-of-sight (LOS)

Point to point. (tower to tower)


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Architecture of WiMAX


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How WiMAX works


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Working1. SS begin scanning presets frequency for base station.

2. BS responds. Synchronizes with SS.

3. Ranging parameters sets UL-MAP messages in everyframe SS bursts with increasing power until itreaches/receives a ranging response from BS.

4. BS responds with timing and power adjustments,management CIDs (connection ID).

5. SS reports its physical layer capabilities(modulation/coding schemes)

6. BS accepts SS; is ready for service flow.

Base

Station

Subscriber

Station


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Security issues


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Loop holes


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Types of layers

MAC layers

Physical layers

PKM (Privacy and Key Management Protocols)


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Security layers


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Physical layer threats

Since PS is above the PHY layer

Jamming

Scrambling

How to avoid

Frequency hopping

Direct sequence spread spectrum

Law enforcement


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MAC Layer Threats Authentication

Lack of BS certificate

Forgeryorreplay attack by mutualauthentication

Denial of Service (DoS)

The attackers try to overload the server

with state transitions operations resulting

in a denial of service attack.


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How to prevent MAC layer threats

Authorization

PKM may suffer from forgery attack due to

unauthenticated BS Avoid by mutual authentication or adding

random challenge text to authentication protocol

AK is generated totally by BS

SS can contributes some bits to generate AK Every certified MAC address should be distinct


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Encryption process for MAC layer


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Security issues inP

KM layer

WiMAX utilizes PKM to establish a

secure link between the BS and SS PKM uses followings to perform key

exchanges between SS and BSX.509 digital certificates

RSA public-key algorithmstrong encryption algorithm


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RSA algorithm


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Conclusion


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security challenges in wimax

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