Quantum cryptography for secure communication in IEEE 802.11 wireless networks

  • Shirantha Wijesekera

    Student thesis: Doctoral Thesis


    IEEE 802.11 is the Wireless Local Area Networks (WLAN) standard developed by the IEEE LAN/MAN Standards Committee. WLANs are increasingly deployed by businesses, government and SOHO users as they offer many advantages to customers with mobility, flexibility and convenience. Wi-Fi is a trademark of the Wi-Fi Alliance that has been used with certified products that belong to a class of WLANs based on the IEEE 802.11 standards. WLANs have become one of the widely used communication systems in the world. It is estimated that there are over 4,00,000 hotspots and millions of Wi-Fi users across the world as of now. Since there are no boundaries in wireless networks, they are more vulnerable to security threats than their wired counterparts. It is possible for an attacker to snoop on confidential communications or modify them to gain access to the wireless networks more easily. Therefore, providing secure communication for wireless networks has become one of the prime concerns. IEEE has made amendments to the initial release of 802.11 standard with the 2004 release of 802.11i,since the former version was found to having security weaknesses in the way it handles authentication and privacy. Quantum Key Distribution (QKD),based on quantum cryptography, offers the promise of unconditional security. QKD enables two parties to distribute a shared random bit string known only to them, which can be used as a key to encrypt and decrypt messages. This research implements a novel method of integrating QKD to distribute the secret key in WLANs. IEEE 802.11i standard uses a 4 way handshake procedure to distribute the key used to encrypt the data communication. In this research, instead of using the 4 way handshake procedure, QKD based key distribution for IEEE 802.11 has been implemented targeting the Counter mode with CBC-MAC Protocol (CCMP) of the Robust Security Network Association (RSNA). Necessary communication flows of existing IEEE 802.11 protocol have been identified and modified. These modifications are done in such a way that only some of the selected fields of the existing protocol have been used to carry QKD specific information. Existing frame formats are not changed, keeping the overall modifications to a minimum. The iv resulting QKD based novel protocol offers unconditional security to the wireless networks with the use of key distributed via QKD. The key distribution process splits into two main communication channels. Firstly, it uses quantum channel to transmit the photons where both parties interpret each photon to a bit (0 or 1) depending on the bases and polarisation used. Secondly it uses classical channel, in this case it is the existing wireless channel, to retrieve the final secured key. Further, a number of possible extensions to IEEE 802.16 (WiMax) and also possibility of merging with IEEE 802.21 standard are also discussed. Several possible enhancements of this research are presented. One such enhancement is the use of Multi Agent Systems (MAS) to deploy the same solution with better control and more efficiently.
    Date of Award2011
    Original languageEnglish
    SupervisorXu Huang (Supervisor) & Dharmendra Sharma AM PhD (Supervisor)

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