Authentication and handoff protocols for wireless mesh networks PhD Security Oral Exam Naif Alamri

Outline Background WMN architecture WMN components WMN challenges Current solutions Related work Future work Auth HandOff WMN / N. Alamri 1/15/2019

Background Mesh topology IEEE 802.11s (2003 – 2011) Multi-hop links Features: self-organization, self-configuration, self-healing Advantages: cost effective, scalable, fault tolerant, increased range Applications: - Last mile broadband access from homes - Backbone for enterprise networks - Extended the range of other networks such as WiMAX - On the fly command centers for emergency response teams, military, etc. Auth HandOff WMN / N. Alamri 1/15/2019

WMN Architectures Three WMN architectures: Infrastructure WMN Dedicated mesh routers connected via mesh links Connect to the Internet using gateways Integrate with wired and wireless networks (bridging or gateway) Client WMN No dedicated mesh routers Clients perform routing, configuration, and maintenance Hybrid WMN Combines the features of infrastructure and client WMNs Client WMN  High throughput, multiple paths Infrastructure WMN  Integration with other radio technologies, reduce power consumption. Auth HandOff WMN / N. Alamri 1/15/2019

WMN Architectures Infrastructure WMN Hybrid WMN Auth HandOff WMN / N. Alamri 1/15/2019

WMN Components Mesh router: Dedicated mesh routers connected via mesh links Connect to the Internet using gateways Integrate with wired and wireless networks (bridging or gateway) Can improve the capacity of the network by using multi-channel single-radio (MCSR) or multi-channel multi-radio (MCMR) Mesh client: Mobile or stationary, power constrained Mostly single radio. Mesh gateway: Connect to the Internet Interoperability between WMNs and other wired and wireless networks Auth HandOff WMN / N. Alamri 1/15/2019

WMN Challenges Routing: Multi-hop, Multi-path, Multi-radio Reactive or Proactive self-organization, self-configuration, self-healing Scalability (overhead), Mobility (handoff) Hybrid Wireless Mesh Protocol (HWMP)  Ad hoc On Demand Distance Vector (AODV) + Radio-Aware metric Security: Confidentiality, Availability, Integrity, authenticity Privacy  Anonymity and Unlinkability Power Efficiency: Power constrained clients. QoS: Path selection, Guarantees, Network capacity, Fairness, Interference Auth HandOff WMN / N. Alamri 1/15/2019

802.11i Introduced in 2004 Enhanced security at MAC layer Also known as Robust Network Security (RNS) Advantages: data protection, mutual authentication, key management Authentication and Confidentiality using WPA2: AES + Counter-mode Cipher Block Chaining Message Authentication Code (CBC-MAC) Protocol (CCMP) Auth HandOff WMN / N. Alamri 1/15/2019

802.1x Part of 802.11i Port-based access control Three elements: Supplicant, Authenticator, Authentication Server Port types: Controlled, Uncontrolled Extensible Authentication protocol (EAP) Transport protocol used by 802.1X Flexible framework Different authentication methods: passwords, certificates, Kerberos, smart cards Auth HandOff WMN / N. Alamri 1/15/2019

EAP authentication methods EAP-TLS EAP-PEAP EAP-TTLS Developed By IETF Cisco, Microsoft, and RSA Funk Software and Meetinghouse Mutual Authentication Yes Secure Links TLS Tunnel Authentication method X.509 Certificates MS-CHAPv2, generic token card, and EAP-TLS CHAP, PAP, MS-CHAPv2, and EAP methods Certificate Required Both sides Server side Protect User Identity No Auth HandOff WMN / N. Alamri 1/15/2019

Security in WMN EAP-TLS for authentication, No fast handoff Extends Robust Security Network Association (RSNA) with Mesh Security Association (MSA) Two key holders: Mesh Authenticator (MA), Mesh Key Distributor (MKD) 802.11s provides secure association between MA and MKD Key hierarchy: Secure link for initial authentication Key generation and distribution Auth HandOff WMN / N. Alamri 1/15/2019

WMN key hierarchy Phase 1: Secure links Supplicant and MKD establish key hierarchy Mutually generate Pairwise Master Key (PMK-MKD) using Pre-Shared Key (PSK) or Master Session Key (MSK) Mutually generate PMK-MA; deliver to MA using MSA Phase 2: Key generation and distribution Pairwise Transient Key (PTK) derived using PMK-MA Group Transient Key (GTK) derived using PMK-MA Auth HandOff WMN / N. Alamri 1/15/2019

WMN Authentication and key generation Auth HandOff WMN / N. Alamri 1/15/2019

Related Work "PAPAR: Pairing Based Authentication Protocol with Anonymous Roaming for Wireless Mesh Networks“ by Sultan et al. (IEEE ICIT, 2014) AS generates a roaming key for each Mesh Access Point Roaming clients can be authenticated using the roaming key of the old MAP AS generates a secondary key and pseudo ID for each mesh client Provides anonymity and unlinkability "An efficient authenticated key establishment scheme for wireless mesh networks“ by He et al. (IEEE GLOBECOM, 2010) A distributed authentication key establishment scheme (AKES) for federated WMNs AS distributes some information to MAPs and clients Information + IDs are used to establish secure connections Auth HandOff WMN / N. Alamri 1/15/2019

Related Work “Ticket-based handoff authentication for wireless mesh networks” by Xu et al. (Computer Networks, 2014) For handoff only, Not initial authentication AS generates tickets using a master key shared with MAPs Ticket used to generate session key No privacy, No unlinkability "Efficient authentication for fast handover in wireless mesh networks“ by Li et al. (Computer & Security, 2013) AS generates multiple tickets for each client One-hop mutual authentication between MAP and client MAP broadcast tickets to neighbors  minimize delay and traffic overhead AS doesn’t participate in handoff Privacy  pseudo IDs Auth HandOff WMN / N. Alamri 1/15/2019

Future Work Task #1: Develop an authentication protocol Design a fast and secure mutual authentication protocol Design a secure key distribution system Add other features such as two-factor, privacy, flexibility Task #2: Develop a handoff protocol Design a ticket-based handoff protocol Design a re-authentication method for seamless roaming Task #3: Test and security evaluation Test the new protocols using a network simulator such as NS3 Build a small testbed to conduct tests and security analysis Design or use existing security evaluation framework for further assessments. Auth HandOff WMN / N. Alamri 1/15/2019

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