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Wired Equivalent Privacy - WEP -

Wired Equivalent Privacy (WEP)

IntroductionOverviewAuthenticationEncryptionDecryptionRecommendsQ&A

Introduction

A wired LAN : physical security

A wireless LAN : radio waves environments

Introduction (Cont)

Introduced in1997Bring the security of wired to wireless

networkThe first and most used-widely algorithm

for wireless network

Ways to Attack

Passive Attacks (Sniffer) Hack WEP Hack WPA, WPA2 Sniffer Packets

Ways to Attack (Cont)

Active Attacks


Jamming Attacks


Man In Middle Attacks

Overview

Protect data privacy WEP (Wired Equivalent Privacy)

Protect data integrity CRC (Cyclic Redundancy Check)

Overview (Cont)

Provide authentication and encryptionAll rely on share keyUses RC4 for encryption

Overview (Cont)

Discard wrong framesUses ICV (Integrity Check Value)

Authentication

Open System AuthenticationShared Key Authentication

Shared Key Authentication

Encryption

Transmission Data

Decryption

XOR

A B A XOR B

1 1 0

1 0 1

0 1 1

0 0 0

What’s Problem ???

IV : 24 bit, small, plain text, staticIV : a part of the RC4 encryption keyICV : not encrypted

Data integrity : not safe

Breaking the Authentication

Collecting :–Clear-text challenge–Encrypted text

Compute the RC4 key

Recommends

Avoid WEP, use WPA or WPA2Don’t use a weak keyChange key periodicallyUses tools

Technology