Security in Wireless Residential Networks

1. Security inWireless Residential Networks Han Sang Kim

2. Introduction • A wide variety of traditional computing devices and embedded Internet appliances will be networked in homes. • One interactive platform. • The broadcast nature of these networks and the heterogeneity of devices on these networks  New security problem

3. Characteristics of Residential Networks • Lack of standardization for devices • Heterogeneity of devices’ capability - Home automation: usually operate at low data - Computer interconnection  The device capability are vastly different with respect to implementation of security mechanisms • Heterogeneous Application - Data traffic, real time service, simple on-off-dim, low data sensor information.

4. Summary • A variety of devices connected by the WRN. The device require and support very different security services, protocols and mechanisms. • New security algorithms and protocols in development will be deployed in consumer electronic devices over time • A unified security standard appears remote and unsuitable for the WRN

5. Requirements • Numerous and inconsistent based on the variety of end-nodes • Support variety of devices, different types of traffic, different applications • Systematically identify the elements in the WRN, their security capabilities and needs • Provide a mechanism which can unify a security architecture for the home

6. Proposed Security Architecture for WRN • Access control for a heterogeneous WRN - device and application dependent • Approach - Device classification - security level classification • Universal access point - algorithm agility - containment security policy

7. Categories of WRN devices • Low data rate low power fixed devices • Low data rate high power fixed devices • Low data rate low power mobile devices • High data rate high power fixed devices • High data rate low power mobile devices • High data rate high power mobile devices

8. Categories of Security Services • No security • Moderate security • Wireline equivalent security • High security • Ultra-high security • Critically high security

9. Algorithm-agile & Containment • Algorithm-agile: support multiple encryption algorithms and apply such algorithms  AP determine what encryption algorithm is applied to an incoming request for access and relay, and act accordingly based on security polices. • Containment: the ability of the network to keep certain security levels of information from leaking out of a particular region.  No traffic from low security device is relayed to a high security device.

10. An example of security mechanism 1. [Dev || Dc || SL || Alg || MACk (Dev || Dc || SL)] Access Point 2. [Ek ( Dc || SL || Rn || TS)] MP3 Player 3. [Dev || Dest || Msg || h(Dest || Msg || Rn +1)] Dev: Device ID Dc: Device category SL: Security level Alg: Algorithm Rn: Nonce Dest: Destination address 4. [Msg || h(Msg || Rn || TS)] PDA

11. Advantages and Limitations • Advantages - security architecture for universal access point - dynamically working - simple to implement and maintain - security mechanism is upgradeable • Limitations - does not solve the simple denial of service - bottleneck at the access point - not appropriate for some devices

12. Our hybrid mechanism • Combine the security categorization mechanism with key distribution mechanism. • Key distribution mechanism: - Master key - Shared network key Access Point Key distribution Or Key update Encrypted by M1 M1 M2 Kn Appliance1 Appliance2 Mn: Master Key Kn: Shared Network Key Communication Encrypted by shared key kn

13. Our hybrid mechanism 1. [ID1 || Dc || SL || Alg || MACmk1 (ID1 || Dc || SL)] Access Point 2. [Emk ( Dc || SL || Rn || TS)] Appliance1 3. [ID1 || Dest|| h(Dest || Rn +1)] 4. [Emk1 ( ID2|| SKey12 || TS)] [Emk2 ( ID1|| SKey12 || TS)] 5. [Eskey12 (ID12 || Msg)] Appliance2

14. What we have done so far and will do? • Implementation our hybrid mechanism by step 4  Yes • Reduction of bottleneck  Yes • Containment police  Yes • Communication between nodes with shared network key  No • Algorithm-agile encryption/decryption  No • Employing other devices  No • Implementing our hybrid mechanism with a sensor  No

15. References [1] H. Nakakita, K. Yamaguchi, M. Hashimoto, T. Saito, and M. Sakurai, “A Study on Secure Wireless Networks Consisting of Home Appliance”, IEEE Transactions on Consumer Electronics, Vol. 49 Issue 2 pp. 375-387, May 2003. [2] P. Krishnamurthy, J. Kabara, and T. Anusas-amornkul, “Security In Wireless Residential Networks”, IEEE Transactions on Consumer Electronics, Vol. 48 No. 1 pp. 157-166, February 2002. [3] Bruce Schneier, “Applied Cryptography”, John Wiley & Sons, 1996 [4] Andrew S. Tanenbaum, “Computer Networks”, Prentice Hall, 1996 [5] J.A. DiGirolamo, “Home networks – from toasters to HDTV”, Digest of Technical Paper in Intl. Conf. On Cons. Electronics, June, 1996. [6] R. Barry, “The future home network – one interactive and entertainment platform”, IEEE Seminar on HomeNet, June 1999. [7] http://www.bluetooth.com [8] C. Kaufman “Network Security: Prentice Hall, 1995 [9] http://security.ece.orst.edu [10] Suman Banerjee, Arunesh Mishra, “Location-based Secure Wireless Group Communication”, Mobile Computing and Communications Review, Volume 1, Number 2