Computational and Energy Costs of Cryptographic Algorithms on Handheld Devices

Networks are evolving toward a ubiquitous model in which heterogeneous devices are interconnected. Cryptographic algorithms are required for developing security solutions that protect network activity. However, the computational and energy limitations of network devices jeopardize the actual implementation of such mechanisms. In this paper, we perform a wide analysis on the expenses of launching symmetric and asymmetric cryptographic algorithms, hash chain functions, elliptic curves cryptography and pairing based cryptography on personal agendas, and compare them with the costs of basic operating system functions. Results show that although cryptographic power costs are high and such operations shall be restricted in time, they are not the main limiting factor of the autonomy of a device

Cryptographic Energy Costs are Assumable in Ad Hoc Networks

Performance of symmetric and asymmetric cryptography algorithms in small devices is presented. Both temporal and energy costs are measured and compared with the basic functional costs of a device. We demonstrate that cryptographic power costs are not a limiting factor of the autonomy of a device and explain how processing delays can be conveniently managed to minimize their impact

Reconfigurable Mobile Multimedia Systems

This paper discusses reconfigurability issues in lowpower hand-held multimedia systems, with particular emphasis on energy conservation. We claim that a radical new approach has to be taken in order to fulfill the requirements - in terms of processing power and energy consumption - of future mobile applications. A reconfigurable systems-architecture in combination with a QoS driven operating system is introduced that can deal with the inherent dynamics of a mobile system. We present the preliminary results of studies we have done on reconfiguration in hand-held mobile computers: by having reconfigurable media streams, by using reconfigurable processing modules and by migrating functions

Overhead Management Strategies for Internet of Things Devices

Overhead (time and energy) management is paramount for IoT edge devices considering their typically resource-constrained nature. In this thesis we present two contributions for lowering resource consumption of IoT devices. The first contribution is minimizing the overhead of the Transport Layer Security (TLS) authentication protocol in the context of IoT networks by selecting a lightweight cipher suite configuration. TLS is the de facto authentication protocol for secure communication in Internet of Things (IoT) applications. However, the processing and energy demands of this protocol are the two essential parameters that must be taken into account with respect to the resource-constraint nature of IoT devices. For the first contribution, we study these parameters using a testbed in which an IoT board (Cypress CYW43907) communicates with a server over an 802.11 wireless link. Although TLS supports a wide-array of cipher suites, in this paper we focus on DHE RSA, ECDHE RSA, and ECDHE ECDSA, which are among the most popular ciphers used due to their robustness. Our studies show that ciphers using Elliptic Curve Diffie Hellman (ECDHE) key exchange are considerably more efficient than ciphers using Diffie Hellman (DHE). Furthermore, ECDSA signature verification consumes more time and energy than RSA signature verification for ECDHE key exchange. This study helps IoT designers choose an appropriate TLS cipher suite based on application demands, computational capabilities, and energy resources available. The second contribution of this thesis is deploying supervised machine learning anomaly detection algorithms on an IoT edge device to reduce data transmission overhead and cloud storage requirements. With continuous monitoring and sensing, millions of Internet of Things sensors all over the world generate tremendous amounts of data every minute. As a result, recent studies start to raise the question as whether to send all the sensing data directly to the cloud (i.e., direct transmission), or to preprocess such data at the network edge and only send necessary data to the cloud (i.e., preprocessing at the edge). Anomaly detection is particularly useful as an edge mining technique to reduce the transmission overhead in such a context when the frequently monitored activities contain only a sparse set of anomalies. This paper analyzes the potential overhead-savings of machine learning based anomaly detection models on the edge in three different IoT scenarios. Our experimental results prove that by choosing the appropriate anomaly detection models, we are able to effectively reduce the total amount of transmission energy as well as minimize required cloud storage. We prove that Random Forest, Multilayer Perceptron, and Discriminant Analysis models can viably save time and energy on the edge device during data transmission. K-Nearest Neighbors, although reliable in terms of prediction accuracy, demands exorbitant overhead and results in net time and energy loss on the edge device. In addition to presenting our model results for the different IoT scenarios, we provide guidelines for potential model selections through analysis of involved tradeoffs such as training overhead, prediction overhead, and classification accuracy

Energy efficient mining on a quantum-enabled blockchain using light

We outline a quantum-enabled blockchain architecture based on a consortium of quantum servers. The network is hybridised, utilising digital systems for sharing and processing classical information combined with a fibre--optic infrastructure and quantum devices for transmitting and processing quantum information. We deliver an energy efficient interactive mining protocol enacted between clients and servers which uses quantum information encoded in light and removes the need for trust in network infrastructure. Instead, clients on the network need only trust the transparent network code, and that their devices adhere to the rules of quantum physics. To demonstrate the energy efficiency of the mining protocol, we elaborate upon the results of two previous experiments (one performed over 1km of optical fibre) as applied to this work. Finally, we address some key vulnerabilities, explore open questions, and observe forward--compatibility with the quantum internet and quantum computing technologies.Comment: 25 pages, 5 figure

The Design of a System Architecture for Mobile Multimedia Computers

This chapter discusses the system architecture of a portable computer, called Mobile Digital Companion, which provides support for handling multimedia applications energy efficiently. Because battery life is limited and battery weight is an important factor for the size and the weight of the Mobile Digital Companion, energy management plays a crucial role in the architecture. As the Companion must remain usable in a variety of environments, it has to be flexible and adaptable to various operating conditions. The Mobile Digital Companion has an unconventional architecture that saves energy by using system decomposition at different levels of the architecture and exploits locality of reference with dedicated, optimised modules. The approach is based on dedicated functionality and the extensive use of energy reduction techniques at all levels of system design. The system has an architecture with a general-purpose processor accompanied by a set of heterogeneous autonomous programmable modules, each providing an energy efficient implementation of dedicated tasks. A reconfigurable internal communication network switch exploits locality of reference and eliminates wasteful data copies

Making Password Authenticated Key Exchange Suitable For Resource-Constrained Industrial Control Devices

Connectivity becomes increasingly important also for small embedded systems such as typically found in industrial control installations. More and more use-cases require secure remote user access increasingly incorporating handheld based human machine interfaces, using wireless links such as Bluetooth. Correspondingly secure operator authentication becomes of utmost importance. Unfortunately, often passwords with all their well-known pitfalls remain the only practical mechanism. We present an assessment of the security requirements for the industrial setting, illustrating that offline attacks on passwords-based authentication protocols should be considered a significant threat. Correspondingly use of a Password Authenticated Key Exchange protocol becomes desirable. We review the signif-icant challenges faced for implementations on resource-constrained devices. We explore the design space and shown how we succeeded in tailoring a partic-ular variant of the Password Authenticated Connection Establishment (PACE) protocol, such that acceptable user interface responsiveness was reached even for the constrained setting of an ARM Cortex-M0+ based Bluetooth low-energy transceiver running from a power budget of 1.5 mW without notable energy buffers for covering power peak transients