WTLS%20(Wireless%20Transport%20Layer%20Security)

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WTLS (Wireless Transport Layer Security)

• Youngho Choung
• Yhchoung_at_cs.uh.edu

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Contents

• Why we need WTLS?
• What is WTLS?
• What is TLS (SSL3.0) ?
• WTLS Functions
• Security Algorithm
• WTLS specifications
• Other Technologies

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Why we need WTLS ? (1/2)

• What can we do through the Cell Phone?
• Communication
• Using Internet
• E-commerce
• On-line banking
• Trading Stock
• Electric Cash
• Electric ID
• Watching movie, take a picture etc ?

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Why we need WTLS ? (2/2)

• Environment problems
• We need Security Solutions

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What is WTLS ? (1/2)
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What is WTLS ? (1/2)
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What is TLS (SSL3.0) ? (1/3)

• TLS stand for Transaction Layer Security
• SSL stand for Secure Socket Layer

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What is TLS (SSL3.0) ? (2/3)
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What is TLS (SSL3.0) ? (3/3)
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WTLS Functions

• Data Integrity
• Privacy
• Authentication
• DoS (Denial of Service) protection
• Optional

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Security AlgorithmHash Function
Any Length Plain Text
Hash Function
MD5, MD4, Hash, SHA-1, etc
Fix length Encrypted Text
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Security AlgorithmBlock Cipher
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Security AlgorithmBlock Cipher
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Security AlgorithmPublic Key

• Key distribution is difficult
• Tow Communicants already share a key or have the
  use of a key distribution center
• Characteristic
• (public) encryption key ? (private) decryption key

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Security AlgorithmPublic Key
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WTLS Specifications (1/5)

• Handshaking protocol
• Full handshaking protocol
• Abbreviated handshaking protocol
• Optimized handshaking protocol
• Alert protocol
• Change Cipher spec protocol
• Record protocol

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WTLS Specifications

• Full handshaking

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WTLS Specifications

• Abbreviated handshaking

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WTLS Specifications

• Optimized full handshaking

ServerHello Certificate ChangeCipherSpec Finishe
d
ChangCipherSpec Finished Application Data
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WTLS Specifications (4/5)

• Alert protocol
• Change Cipher spec protocol

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WTLS Specifications (5/5)

• Record Protocol

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Lets talk aboutlater..?

• WALS(Wireless Application Layer Security)
• WPKI(Wireless Public-Key Infrastructure)
• WIM(WAP Identity Module References