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

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

• Advisor Dr. Kai-Wei Ke
• Speaker Yen-Jen Chen
• Date 06/24/2008

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Outline

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

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Outline

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

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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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IEEE 802.16 Security Architecture
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IEEE 802.16 Security Process
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Authentication
Key lifetime 1 to 70 days , usually 7days
SS ?BS Cert(Manufacturer(SS)) SS ?BS Cert(SS)
Capabilities SAID BS ?SS RSA-Encrypt(PubKey(SS)
, AK) Lifetime SeqNo SAIDList
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Key Derivation

• KEK Truncate-128(SHA1(((AK 044) xor 5364)
• Downlink HMAC key SHA1((AK044) xor 3A64)
• Uplink HMAC key SHA1((AK044) xor 5C64)

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Data Key Exchange
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Data Encryption
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IEEE 802.16 Security Process
BS
SS
1.??SS?? 2.??AK, ??????public key????
?AK??
1.??SHA?????HMAC-Digest 2.??TEK 3.?AK??KEK????TEK
1.??SHA??HMAC-Digest 2.?AK???KEK???TEK
HMAC-Digest??????????
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Outline

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

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Security Architecture
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WiMAX PKMv2 Protocol
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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

• RSA based authentication
• Use the PKMv2 RSA-Request?PKMv2 RSA-Reply?PKMv2
  RSA-Reject?PKMv2 RSA-acknowledgement messages to
  get pre-PAK
• Using the public key of SS to encrypt the pre-PAK
  and send back to SS
• pre-PAK generates the PAK (Primary Authorization
  key) and EIK(EAP integrity Key)
• PAK generates the AK

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EAP authentication protocol (Cont.)

• RSA based authentication
• EIKPAK lt Dot16KDF (pre-PAK,SS MAC address
  BSID EIKPAK , 320)
• AKlt Dot16KDF (PAK,SS MAC address BSID
  PAKAK , 160)

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EAP authentication protocol (Cont.)

• One level EAP based authentication
• Using the authentication exchange message to get
  MSK (Master session key)
• PMKlt truncate(MSK,160)
• AKltDot16KDF(PMK,SS MAC Address BSID
  AK,160)

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EAP authentication protocol (Cont.)

• Two level EAP based authentication
• SS sent the PKEv2 EAP Start to BS
• The first EAP negotiation will begin between BS
  and SS included the message of PKMv2
  Transfer2(MSK)
• After that BS will send the EAP-Success or
  EAP-failure.
• If BS sent the EAP-Success then BS will send the
  PKMv2_EAP_Complete encrypted by EIK immediate
• If SS gets the EIK and PMK successful then SS can
  verify the message
• Otherwise the SS might get the EAP-failure or get
  no respond to show that BS is failure to
  authentication

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EAP authentication protocol (Cont.)

• Two level EAP based authentication
• After SS finished the first EAP negotiation
  successful ,the SS will send PKMv2 Authenticated
  EAP Start to start the second EAP negotiation
• When BS got this message, BS will check the
  message by EIK.
• If BS check ok then BS will start the second EAP
  negotiation, otherwise BS will think the
  Authenticated failure.
• The related messages of PKM is protected by EIK
  in the second EAP negotiation
• If BS and SS competed second EAP negotiation,
  then BS and SS can get the AK form PMK( pairwise
  authorization key) and PMK2

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EAP authentication protocol (Cont.)

• Two level EAP based authentication
• EIKPMK lt truncate (MSK,320)
• PMK2 lt truncate(MSK,160)
• AK lt Dot 16KDF(PMK PMK2, SS MAC Address
  BSID AK , 160)

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EAP authentication protocol (Cont.)

• RSA based authentication followed by EAP
  authentication
• First execute RSA-based authorization and execute
  the second round of Double EAP mode
• EIKPAK lt Dot16KDF(pre-PAK, SS MAC Address
  BSID EIKPAK,320)
• AK lt Dot16KDF(PAK?PMK, SS MAC Address BSID PAK
  AK 160)

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Key hierarchy in the 802.16e

• TEK (Traffic Encryption Key)
• TEK is generated by random number of BS
• BS use the KEK to encrypt the TEK and send to SS
• TEK is used to encrypt the message or data
  between BS and SS

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

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System Architecture
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System Architecture

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

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Outline

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

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Subsystem design

• Data Privacy Subsystem

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Subsystem design

• Authentication Subsystem

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Subsystem design

• Key management Subsystem

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Outline

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

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System flow
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System flow

• Uplink Flow

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System flow

• Downlink Flow

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Outline

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

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System over embedded system
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System over embedded system

• Central Controller Communication
• Layered Communication

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System over embedded system

• Class Diagram

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Outline

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

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System test
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System test
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System test

• Note 140.124.183.50?SS?IP,140.124.183.220?BS?IP,1
  40.124.183.230?relay node IP
• Number 1047 and 1054,show that SS send the first
  cert to BS
• Number 1060 and 1092,show that BS send the ACK to
  BS
• Number 1259 and 1260,show that SS send the second
  cert to BS
• Number 1454 and 1455,show that BS send the ACK to
  BS
• Number 1998 and 1999,show that SS send the
  TEK-REQ to BS
• Number 2458 and 2459,show that BS send the TEK to
  SS

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Outline

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

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Conclusion and future work

• The System success porting over embedded system
• Provide the security sublayer module of
  802.16d and part of 802.16e
• Porting the CPS of MAC over embedded system
• Add the authentication of 802.16e

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Outline

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

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References

• IEEE Standard for Local and metropolitan area
  networks Part 16Air Interface for Fixed
  Broadband Wireless Access Systems,IEEE Std
  802.16-2004
• IEEE Standard for Local and metropolitan area
  networks Part 16Air Interface for Fixed and
  Mobile Broadband Wireless Access Systems,IEEE Std
  802.16e-2005
• Johnson, David and Walker, Jesse of Intel (2004),
  Overview of IEEE 802.16 Security ,published by
  the IEEE computer society
• http//www.seas.gwu.edu/cheng/388/LecNotes2006/
• WiMAX ??????? ,??????????? ,?????? T96006
• IEEE 802.16e-2005 WiMAX??????, ????????????,
  ?????, 119?, 2007/03