Technical Reports (2004 - 2009)

Authors of Technical Reports (2005-2009): Choueiry, Berthe Cohen, Myra Deogun, Jitender Dwyer, Matthew Elbaum, Sebastian Goddard, Steve Henninger, Scott Jiang, Hong Lu, Ying Ramamurthy, Byrav Rothermel, Gregg Scott, Stephen Seth, Sharad Soh, Leen-Kiat Srisa-an, Witty Swanson, David Variyam, Vinodchandran Wang, Jun Xu, Lison

Key revocation in wireless sensor networks: a survey on a less-addressed yet vital issue

Key management in wireless sensor network (WSN) includes two important aspects namely key distribution, which constitutes the task of distributing secret keys to nodes in the network, and key revocation, which refers to the task of securely withdrawing the key information relating to any compromised node or because of tactical reasons. While in the existing literature, key distribution has been extensively studied, key revocation has received relatively little attention. A vital security issue like this needs proper recognition to be considered as a critical research area, not just as a partial segment of key management. With this motivation, in this paper, we present our rationale behind recognising the area and analyse the state-of-the-art key revocation techniques. Alongside our survey on the prominent schemes, we also present an analysis of security and performance that highlights the advantages and disadvantages of each scheme that explicitly mentions the method of key revocation

An Efficient Scheme for Removing Compromised Sensor Nodes from Wireless Sensor Networks

Key management is a core mechanism to ensure the security of applications and network services in wireless sensor networks. It includes two aspects: key distribution and key revocation. Key distribution has been extensively studied in the context of sensor networks. However, key revocation has received relatively little attention. Existing key revocation schemes can be divided into two categories: centralized key revocation scheme and distributed key revocation scheme. In this paper, we first review and summarize the current key revocation schemes for sensor networks. Then, we present an efficient scheme of removing compromised sensor nodes from wireless sensor networks. Unlike most sensor node removal schemes focusing on removing the compromised keys, the proposed scheme, KeyRev, uses key update techniques to obsolesce the keys owned by the compromised sensor nodes and thus remove the nodes from the network. Our analyses show that the KeyRev scheme is secure inspite of not removing the pre-distributed key materials at com- promised sensor nodes. Simulation results also indicate that the KeyRev scheme is scalable and performs very well compared with other key revocation schemes in wireless sensor networks

Location dependent key management schemes supported by random selected cell reporters in wireless sensor networks

PhD ThesisIn order to secure vital and critical information inside Wireless Sensor Net- works (WSNs), a security requirement of data con dentiality, authenticity and availability should be guaranteed. The leading key management schemes are those that employ location information to generate security credentials. Therefore, this thesis proposes three novel location-dependent key manage- ment schemes. First, a novel Location-Dependent Key Management Protocol for a Single Base Station (LKMP-SBS) is presented. As a location-dependent scheme, the WSN zone is divided virtually into cells. Then, any event report generated by each particular cell is signed by a new type of endorsement called a cell- reporter signature, where cell-reporters are de ned as a set of nodes selected randomly by the BS out of the nodes located within the particular cell. This system is analysed and proved to outperform other schemes in terms of data security requirements. Regarding the data con dentiality, for three values of z (1,2,3) the improvement is 95%, 90% and 85% respectively when 1000 nodes are compromised. Furthermore, in terms of data authenticity an enhancement of 49%, 24%, 12.5% is gained using our approach with z = 1; 2; 3 respectively when half of all nodes are compromised. Finally, the optimum number of cell reporters is extensively investigated related to the security requirements, it is proven to be z = n 2 . The second contribution is the design of a novel Location-Dependent Key Man- agement Protocol for Multiple Base Stations (LKMP-MBS). In this scheme, di erent strategies of handling the WSN by multiple BSs is investigated. Ac- cordingly, the optimality of the scheme is analysed in terms of the number of cell reporters. Both data con dentiality and authenticity have been proven to be / e / 1 N . The optimum number of cell reporters had been calculated as zopt = n 2M , PM `=1 jz(`) optj = n 2M . Moreover, the security robustness of this scheme is analysed and proved to outperform relevant schemes in terms of data con- dentiality and authenticity. Furthermore, in comparison with LKMP-SBS, the adoption of multiple base stations is shown to be signi cantly important in improving the overall system security. The third contribution is the design of the novel Mobility- Enabled, Location- dependant Key Managment Protocol for Multiple BSs (MELKMP-MBS). This scheme presents a key management scheme, which is capable of serving a WSN with mobile nodes. Several types of handover are presented in order to main- tain the mobile node service availability during its movement between two zones in the network. Accordingly, the communication overhead of MELKMP- MBS is analysed, simulated and compared with the overhead of other schemes. Results show a signi cant improvement over other schemes in terms of han- dover e ciency and communication over head. Furthermore, the optimality of WSN design such as the value of N; n is investigated in terms of communi- cation overhead in all protocols and it is shown that the optimum number of nodes in each cell, which cause the minimum communication overhead in the network , is n = 3 p 2N.Ministry of Higher Education and Scienti c Research in Iraq and the Iraqi Cultural Attach e in Londo