WiMAX?????????????????

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WiMAX?????????????????
The research and implementation of WiMAX security
subsystem over an embedded system

• Speaker Yen-Jen Chen (???)
• Advisor Dr. Kai-Wei Ke (??? ??)
• Date 07/28/2008

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Outline

• Introduction
• Overview of IEEE 802.16-2004 Security
• Overview of IEEE 802.16e-2005 Security
• IEEE 802.16-2004 Security Sublayer Implementation
• System Architecture
• Subsystem design
• System flow
• System over embedded system
• System test
• Conclusion and Future Work

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MAC Privacy Sub-layer

• Provides secure communication
• Data encrypted with cipher clock chaining mode of
  DES
• Prevents theft of service
• SSs authenticated by BS using key management
  protocol

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Security Architecture
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Authentication
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Key Derivation
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Data Key Exchange
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Data Encryption
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Outline

• Introduction
• Overview of IEEE 802.16-2004 Security
• Overview of IEEE 802.16e-2005 Security
• IEEE 802.16-2004 Security Sublayer Implementation
• System Architecture
• Subsystem design
• System flow
• System over embedded system
• System test
• Conclusion and Future Work

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Security Architecture
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EAP authentication protocol

• EAP is a authentication framework not a specially
  authentication mechanism
• the four methods in 802.16e
• RSA based authentication
• One level EAP based authentication
• Two level EAP based authentication
• RSA based authentication followed by EAP
  authentication

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EAP authentication protocol (Cont.)

• RSA based
• authentication
• One level EAP
• based
  authentication

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EAP authentication protocol (Cont.)

• Two level EAP
• based authentication
• RSA based
  authentication
• followed by
  EAP
• 
  authentication

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Key hierarchy in the 802.16e
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Key hierarchy in the 802.16e
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Outline

• Introduction
• Overview of IEEE 802.16-2004 Security
• Overview of IEEE 802.16e-2005 Security
• IEEE 802.16-2004 Security Sublayer Implementation
• System Architecture
• Subsystem design
• System flow
• System over embedded system
• System test
• Conclusion and Future Work

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System Architecture

• Data Privacy subsystem (DPS)
• Get the data form different system
• Verify the data if encrypt or decrypt
• Dispatch the data to the subsystem

• Authentication subsystem (AS)
• Verify the certification
• Add the relative information
• Generate the AK (New one or Update old)

• Key Management subsystem (KMS)
• Save the information of the keys (TEK KEK
  HMAC-key etc.)
• Use AK to Generate key (KEK HMAC-key)
• Generate the TEKs (New one or Update old)

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• Data Privacy subsystem (DPS)
• Get the data form different system
• Verify the data if encrypt or decrypt
• Dispatch the data to the subsystem
• Authentication subsystem (AS)
• Verify the certification
• Add the relative information
• Generate the AK (New one or Update old)
• Key Management subsystem (KMS)
• Save the information of the key (TEK KEK
  HMAC-keys etc.)
• Use AK to Generate key (KEK HMAC-key)
• Generate the TEK (New one or Update old)

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Subsystem design (Data Privacy Subsystem)

• Data Encryption Function
• Get key from Key Management
• subsystem
• Get the security algorithm from
• Security Suit Function

• Data Decryption Function
• Get key from Key Management subsystem
• Get the security algorithms from Security Suit
  Function
• Send the TEK relative information to key
  management subsystem
• Send the certification to Authentication
  subsystem

• Security Suit Function
• Provide the different encrypt/decrypt algorithms
  and signature algorithm

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• Data Encryption Function
• Get key from key management
• subsystem
• Get the security algorithm from
• Security Suit Function
• Data Decryption Function
• Get key from key management subsystem
• Get the security algorithms from Security Suit
  Function
• Send the tek relative information to key
  management subsystem
• Send the certification to Authentication
  subsystem
• Security Suit Function
• Provide the different encrypt/decrypt algorithms
  and signature algorithm

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Subsystem design (Authentication Subsystem)

• Content Checker function
• Send the AK relative information to AK Checker
• Send the Certification relative information to
  Certification Checker
• Get AK back from AK Checker or Certification
  Checker

• AK Checker function
• Get AK relative information from Content Checker
• Send AK generate message to AK Generator
• Send AK back to Content Checker

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• Content Checker function
• Send the AK relative information to AK Checker
• Send the Certification relative information to
  Certification Checker
• Get AK back from AK Checker or Certification
  Checker
• AK Checker function
• Get AK relative information from Content Checker
• Send AK generate message to AK Generator
• Send AK back to Content Checker

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Subsystem design (Authentication Subsystem)

• Certification Checker function
• Get Certification from Content Checker
• Send AK generate message to AK Generator
• Send AK back to Content Checker

• AK Generator function
• Get AK generate message from AK Checker or
  Certification Checker
• Send new AK to Key management subsystem, AK
  Checker ,Certification Checker

• Certification Checker function
• Get Certification from Content Checker
• Send AK generate message to AK Generator
• Send AK back to Content Checker
• AK Generator function
• Get AK generate message from AK Checker or
  Certification Checker
• Send new AK to Key management subsystem, AK
  Checker ,Certification Checker

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Subsystem design(Key management Subsystem)

• Content Checker Function
• Get key request or TEK relative information from
  DPS
• Send key request to Key checker
• Send TEK relative information to TEK Checker
• Get new TEK or Request key info

• Key Checker Function
• Get key request message from Content Checker
• Get request key from Key Pool
• Send request key to Content Checker

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• Content Checker Function
• Get key request or tek relative information from
  DPS
• Send key request to Key checker
• Send tek relative information to TEK Checker
• Get new TEK or Request key info
• Key Checker Function
• Get key request message from Content Checker
• Get request key from Key Pool
• Send request key to Content Checker

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Subsystem design(Key management Subsystem)

• TEK Checker Function
• Get TEK relative information from Content Checker
• Send key generate message to Key Generator
• Get new TEK form Key Generator

• Key Generator Function
• Get key generator message from TEK Checker
• Get New AK info from AS

• Key Pool Function
• Get new key info form Key Generator
• Send back the request key info

• TEK Checker Function
• Get TEK relative information from Content Checker
• Send key generate message to Key Generator
• Get new TEK form Key Generator
• Key Generator Function
• Get key generator message from TEK Checker
• Get New AK info from AS
• Key Pool Function
• Get new key info form Key Generator
• Send back the request key info

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System flow (Uplink)
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System flow (Downlink)
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System over embedded system
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System over embedded system

• Central Controller Communication
• Pros.
• Easy to implement
• Cons.
• Need extra effort
• Every sublayer do not
• Know the existence of
• others

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System over embedded system

• Layered Communication
• Pros.
• Easy to do cross sublayer
• information exchange
• Cons.
• More complicated implementation

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System over embedded system

• Class Diagram
• Data Generator Object
• Application class
• WiMAX Sublayer Object
• CSInterface class
• CommonPart class
• C_Sec_Core class
• Layer Controller Object
• Ctrl_CSInterface class
• Ctrl_CommonPart class
• Ctrl_ C_Sec_Core class
• Ctrl_Interface class
• Network Object
• Transmission class

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System test
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System test

• 140.124.183.222 is the IP of SS
• 140.124.183.221 is the IP of BS
• 140.124.183.230 is the IP of relay node

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System test

• Test 1 and Test 2 show that
• the system uses the different
• encrypt/decrypt algorithm
• (Exp 1)
• After the Test 1 and Test 2 the
• System Starts TEK key Request Procedure
• (Exp 2)

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System test

• Test 3 and Test 4 show that the
• system uses the second TEK
• (Exp 3)
• Test 5 shows that the system uses
• the new TEK which got at Exp 2
• (Exp 5)

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Outline

• Introduction
• Overview of IEEE 802.16-2004 Security
• Overview of IEEE 802.16e-2005 Security
• IEEE 802.16-2004 Security Sublayer Implementation
• System Architecture
• Subsystem design
• System flow
• System over embedded system
• System test
• Conclusion and Future Work

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Conclusion and future work

• Authentication
• X.509 certification exchange and verify
• Provide AK generator
• Update the AK before the lifetime end
• Key Management
• Manage the keys as KEK,TEK,HMAC keys
• Provide the Key Generator
• Keep the key fresh
• Update the TEK before the lifetime end
• Data privacy
• Data encrypt/decrypt algorithms (DES-CBC
  ,AES-CCM)
• Key encrypt/decrypt algorithms (3DES,AES-ECB)
• Digest algorithms (HMAC-SHA1,HMAC-RSA)

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Conclusion and future work

• Provide the security sublayer modules of 802.16d
  and 802.16e and reserve authentication
  architecture of 802.16e over the embedded system
• Integrate CS and CPS over embedded system
• Add the authentication of 802.16e
• Directly connect

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Any Question?
Any
Questions
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Thanks for your listening
You !
Thank
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System test

• Test1 and Test2 show that
• the system uses the different
• encrypt/decrypt algorithm (Step1)
• Test3 and Test4 show that the
• system uses the second TEK
• Test5 shows that the system
• use the new TEK which got at Step2