An Energy Aware and Secure MAC Protocol for Tackling Denial of Sleep Attacks in Wireless Sensor Networks

Wireless sensor networks which form part of the core for the Internet of Things consist of resource constrained sensors that are usually powered by batteries. Therefore, careful energy awareness is essential when working with these devices. Indeed,the introduction of security techniques such as authentication and encryption, to ensure confidentiality and integrity of data, can place higher energy load on the sensors. However, the absence of security protection c ould give room for energy drain attacks such as denial of sleep attacks which have a higher negative impact on the life span ( of the sensors than the presence of security features. This thesis, therefore, focuses on tackling denial of sleep attacks from two perspectives A security perspective and an energy efficiency perspective. The security perspective involves evaluating and ranking a number of security based techniques to curbing denial of sleep attacks. The energy efficiency perspective, on the other hand, involves exploring duty cycling and simulating three Media Access Control ( protocols Sensor MAC, Timeout MAC andTunableMAC under different network sizes and measuring different parameters such as the Received Signal Strength RSSI) and Link Quality Indicator ( Transmit power, throughput and energy efficiency Duty cycling happens to be one of the major techniques for conserving energy in wireless sensor networks and this research aims to answer questions with regards to the effect of duty cycles on the energy efficiency as well as the throughput of three duty cycle protocols Sensor MAC ( Timeout MAC ( and TunableMAC in addition to creating a novel MAC protocol that is also more resilient to denial of sleep a ttacks than existing protocols. The main contributions to knowledge from this thesis are the developed framework used for evaluation of existing denial of sleep attack solutions and the algorithms which fuel the other contribution to knowledge a newly developed protocol tested on the Castalia Simulator on the OMNET++ platform. The new protocol has been compared with existing protocols and has been found to have significant improvement in energy efficiency and also better resilience to denial of sleep at tacks Part of this research has been published Two conference publications in IEEE Explore and one workshop paper

Securing Restricted Publisher-Subscriber Communications in Smart Grid Substations

Smart Grid applications require accurate and correct data transmission from publisher to subscribers with critical communication latency requirements. Since the smart grid is being supported by distributed communication networks, deployed using various wired and wireless technologies, including IP-based networks, securing the communication infrastructure is both critically important and challenging. In this paper, we propose a secure and efficient data delivery scheme, based on a restricted yet dynamic publisher-subscriber architecture, for the published messages from a publisher to the subscribers distributed in the smart grid network. The scheme ensures that the published message is delivered from an authentic publisher to only those authorized subscribers by verifying publisher's signature and access structure of all subscribers. Operation overheads are reduced by performing only one encryption and decryption or hashing per subscriber location using a proxy node as a remote terminal unit. Our analysis shows that the scheme is resistant against replay, man-in-the-middle, and impersonation attacks. Performance evaluation shows that the scheme can support 600 subscribers given the communication latency requirement of 3 ms. We provide the performance of the scheme under different scenarios, and observe that the efficiency of our scheme increases as the ratio of the geographical locations within a substation to the number of subscribers increases

Memory Encryption for Smart Cards Barı¸s Ege 1, Elif Bilge Kavun 2,andTolgaYalçın 2

Abstract. With the latest advances in attack methods, it has become increasingly more difficult to secure data stored on smart cards, especially on non-volatile memories (NVMs), which may store sensitive information such as cryptographic keys or program code. Lightweight and low-latency cryptographic modules are a promising solution to this problem. In this study, memory encryption schemes using counter (CTR) and XOR-Encrypt-XOR (XEX) modes of operation are adapted for the target application, and utilized using various implementations of the block ciphers AES and PRESENT. Both schemes are implemented with a block cipher-based address scrambling scheme, as well as a special write counter scheme in order to extend the lifetime of the encryption key in CTR-mode. Using the lightweight cipher PRESENT, it is possible to implement a smart card NVM encryption scheme with less than 6K gate equivalents and zero additional latency

A Fast and Scalable Authentication Scheme in IoT for Smart Living

Numerous resource-limited smart objects (SOs) such as sensors and actuators have been widely deployed in smart environments, opening new attack surfaces to intruders. The severe security flaw discourages the adoption of the Internet of things in smart living. In this paper, we leverage fog computing and microservice to push certificate authority (CA) functions to the proximity of data sources. Through which, we can minimize attack surfaces and authentication latency, and result in a fast and scalable scheme in authenticating a large volume of resource-limited devices. Then, we design lightweight protocols to implement the scheme, where both a high level of security and low computation workloads on SO (no bilinear pairing requirement on the client-side) is accomplished. Evaluations demonstrate the efficiency and effectiveness of our scheme in handling authentication and registration for a large number of nodes, meanwhile protecting them against various threats to smart living. Finally, we showcase the success of computing intelligence movement towards data sources in handling complicated services.Comment: 15 pages, 7 figures, 3 tables, to appear in FGC

Efficient Key Management Schemes for Smart Grid

With the increasing digitization of different components of Smart Grid by incorporating smart(er) devices, there is an ongoing effort to deploy them for various applications. However, if these devices are compromised, they can reveal sensitive information from such systems. Therefore, securing them against cyber-attacks may represent the first step towards the protection of the critical infrastructure. Nevertheless, realization of the desirable security features such as confidentiality, integrity and authentication relies entirely on cryptographic keys that can be either symmetric or asymmetric. A major need, along with this, is to deal with managing these keys for a large number of devices in Smart Grid. While such key management can be easily addressed by transferring the existing protocols to Smart Grid domain, this is not an easy task, as one needs to deal with the limitations of the current communication infrastructures and resource-constrained devices in Smart Grid. In general, effective mechanisms for Smart Grid security must guarantee the security of the applications by managing (1) key revocation; and (2) key exchange. Moreover, such management should be provided without compromising the general performance of the Smart Grid applications and thus needs to incur minimal overhead to Smart Grid systems. This dissertation aims to fill this gap by proposing specialized key management techniques for resource and communication constrained Smart Grid environments. Specifically, motivated by the need of reducing the revocation management overhead, we first present a distributed public key revocation management scheme for Advanced Metering Infrastructure (AMI) by utilizing distributed hash trees (DHTs). The basic idea is to enable sharing of the burden among smart meters to reduce the overall overhead. Second, we propose another revocation management scheme by utilizing cryptographic accumulators, which reduces the space requirements for revocation information significantly. Finally, we turn our attention to symmetric key exchange problem and propose a 0-Round Trip Time (RTT) message exchange scheme to minimize the message exchanges. This scheme enables a lightweight yet secure symmetric key-exchange between field devices and the control center in Smart Gird by utilizing a dynamic hash chain mechanism. The evaluation of the proposed approaches show that they significantly out-perform existing conventional approaches