Performance Evaluation of Cryptographic Algorithms over IoT Platforms and Operating Systems

The deployment of security services over Wireless Sensor Networks (WSN) and IoT devices brings significant processing and energy consumption overheads. These overheads are mainly determined by algorithmic efficiency, quality of implementation, and operating system. Benchmarks of symmetric primitives exist in the literature for WSN platforms but they are mostly focused on single platforms or single operating systems. Moreover, they are not up to date with respect to implementations and/or operating systems versions which had significant progress. Herein, we provide time and energy benchmarks of reference implementations for different platforms and operating systems and analyze their impact. Moreover, we not only give the first benchmark results of symmetric cryptography for the Intel Edison IoT platform but also describe a methodology of how to measure energy consumption on that platform

Key Management in Wireless Sensor Networks, IP-Based Sensor Networks, Content Centric Networks

Cryptographic keys and their management in network communication is considered the main building block of security over which other security primitives are based. These cryptographic keys ensure the privacy, authentication, integrity and non-repudiation of messages. However, the use of these cryptographic keys and their management in dealing with the resource constrained devices (i.e. Sensor nodes) is a challenging task. A number of key management schemes have been introduced by researchers all over the world for such resource constrained networks. For example, light weight PKI and elliptic curve cryptography schemes are computationally expensive for these resource constrained devices. So far the symmetric key approach is considered best for these constrained networks and different variants of it been developed for these networks (i.e. probabilistic key distribution approach). The probabilistic key distribution approach consumes less memory than the standard symmetric key approach but it suffers from the connectivity issues (i.e. the connectivity depends on the common shared keys between the nodes). Most of those schemes were proposed by considering static sensor networks (e.g. Industrial process monitoring, Environmental monitoring, movement detection in military applications, forests etc.). However, the use of these existing key management schemes for mobile wireless sensor networks applications introduces more challenges in terms of network connectivity, energy consumption, memory cost, communication overhead and protection of key materials against some well known attacks. Keeping these challenges in mind, previous research has proposed some key management schemes considering the mobility scenarios in ad hoc networks and wireless sensor networks (e.g. vehicular networks, health monitoring systems).However these schemes consume more resource because of a much higher communication packet exchange during the handover phase for the authentication of joining and leaving nodes than the static networks where there is no extra communication for the handover and authentication. The motivation of this research work is to investigate and propose new algorithms not only to improve the efficiency of these existing authentication and key management schemes in terms of connectivity, memory and security by considering the mobility scenario in wireless sensor networks, but also to develop new algorithms that suit these constrained networks than the existing schemes. First, we choose the existing key pool approach for authentication and key management and improve its network connectivity and resilience against some well known attacks (e.g. node capturing attacks) while reduce the memory cost by storing those key pools in each sensor node. In the proposed solution, we have divided the main key pool into two virtual mutually exclusive key pools. This division and constructing a key from two chosen keys, one from each key pool, helps to reduce the memory cost of each node by assigning fewer keys for the same level of network connectivity as the existing key pool frameworks. Although, the proposed key pool approach increases the network resilience against node compromission attacks because of the smaller number of keys assigned to each node, however it does not completely nullify the effect of the attacks. Hence we proposed an online mutual authentication and key establishment and management scheme for sensor networks that provides almost 100\% network connectivity and also nullifies the effect of node compromission attacks. In the proposed online key generation approach, the secret key is dependent on both communicating parties. Once the two communicating parties authenticate each other, they would successfully establish a secret communication key, otherwise they stop communication and inform the network manager about the intruder detection and activity. The last part of the thesis considers the integration of two different technologies (i.e. wireless sensor networks and IP networks). This is a very interesting and demanding research area because of its numerous applications, such as smart energy, smart city etc.. However the security requirements of these two kind of networks (resource constrained and resourceful) make key management a challenging task. Hence we use an online key generation approach using elliptic curve cryptography which gives the same security level as the standard PKI approach used in IP networks with smaller key length and is suited for the sensor network packet size limitations. It also uses a less computationally expensive approach than PKI and hence makes ECC suitable to be adopted in wireless sensor networks. In the key management scheme for IP based sensor networks, we generate the public private key pair based on ECC for each individual sensor node. However the public key is not only dependent on the node's parameter but also the parameters of the network to which it belongs. This increases the security of the proposed solution and avoids intruders pretending to be authentic members of the network(s) by spreading their own public keys. In the last part of the thesis we consider Content Centric Networking (CCN) which is a new routing architecture for the internet of the future. Building on the observation that today's communications are more oriented towards content retrieval (web, P2P, etc.) than point-to-point communications (VoIP, IM, etc.), CCN proposes a radical revision of the Internet architecture switching from named hosts (TCP/IP protocols) to named data to best match its current usage. In a nutshell, content is addressable, routable, self-sufficient and authenticated, while locations no longer matter. Data is seen and identified directly by a routable name instead of a location (the address of the server). Consequently, data is directly requested at the network level not from its holder, hence there is no need for the DNS). To improve content diffusion, CCN relies on data distribution and duplication, because storage is cheaper than bandwidth: every content - particularly popular one - can be replicated and stored on any CCN node, even untrustworthy. People looking for particular content can securely retrieve it in a P2P-way from the best locations available. So far, there has been little investigation of the security of CCNs and there is no specific key management scheme for that. We propose an authentication and key establishment scheme for CCNs in which the contents are authenticated by the content generating node, using pre-distributed shares of encryption keys. The content requesting node can get those shares from any node in the network, even from malicious and intruder ones, in accordance with a key concept of CCNs. In our work we also provide means to protect the distributed shares from modification by these malicious/intruder nodes. The proposed scheme is again an online key generation approach but including a relation between the content and its encryption key. This dependency prevents the attackers from modifying the packet or the key shares

Técnicas de segurança para a internet das coisas

Mestrado em Engenharia de Computadores e TelemáticaIoT assume que dispositivos limitados, tanto em capacidades computacionais como em energia disponível, façam parte da sua infraestrutura. Dispositivos esses que apresentam menos capacidades e mecanismos de defesa do que as máquinas de uso geral. É imperativo aplicar segurança nesses dispositivos e nas suas comunicações de maneira a prepará-los para as ameaças da Internet e alcançar uma verdadeira e segura Internet das Coisas, em concordância com as visões atuais para o futuro. Esta dissertação pretende ser um pequeno passo nesse sentido, apresentando alternativas para proteger as comunicações de dispositivos restritos numa perspetiva de performance assim como avaliar o desempenho e a ocupação de recursos por parte de primitivas criptográficas quando são aplicadas em dispositivos reais. Dado que a segurança em diversas ocasiões tem de se sujeitar aos recursos deixados após a implementação de funcionalidades, foi colocada uma implementação de exposição de funcionalidades, recorrendo ao uso de CoAP, num dispositivo fabricado com intenção de ser usado em IoT e avaliada de acordo com a sua ocupação de recursos.IoT comprehends devices constrained in both computational capabilities and available energy to be a part of its infrastructure. Devices which also present less defense capabilities and mechanisms than general purpose machines. It’s imperative to secure such devices and their communications in order to prepare them for the Internet menaces and achieve a true and secure Internet of Things compliant with today’s future visions. This dissertation intends to be a small step towards such future by presenting alternatives to protect constrained device’s communications in a performance related perspective as well as benchmarks and evaluation of resources used by cryptographic primitives when implemented on real devices. Due to security being on multiple occasions subjected to the resources available only after functionalities implementation, a minimalist implementation of functionalities exposure through the use of CoAP was also deployed in an IoT intended device and assessed according to resource overhead

Key Management in Wireless Sensor Networks, IP-Based Sensor Networks, Content Centric Networks

Cryptographic keys and their management in network communication is considered the main building block of security over which other security primitives are based. These cryptographic keys ensure the privacy, authentication, integrity and non-repudiation of messages. However, the use of these cryptographic keys and their management in dealing with the resource constrained devices (i.e. Sensor nodes) is a challenging task. A number of key management schemes have been introduced by researchers all over the world for such resource constrained networks. For example, light weight PKI and elliptic curve cryptography schemes are computationally expensive for these resource constrained devices. So far the symmetric key approach is considered best for these constrained networks and different variants of it been developed for these networks (i.e. probabilistic key distribution approach). The probabilistic key distribution approach consumes less memory than the standard symmetric key approach but it suffers from the connectivity issues (i.e. the connectivity depends on the common shared keys between the nodes). Most of those schemes were proposed by considering static sensor networks (e.g. Industrial process monitoring, Environmental monitoring, movement detection in military applications, forests etc.). However, the use of these existing key management schemes for mobile wireless sensor networks applications introduces more challenges in terms of network connectivity, energy consumption, memory cost, communication overhead and protection of key materials against some well known attacks. Keeping these challenges in mind, previous research has proposed some key management schemes considering the mobility scenarios in ad hoc networks and wireless sensor networks (e.g. vehicular networks, health monitoring systems).However these schemes consume more resource because of a much higher communication packet exchange during the handover phase for the authentication of joining and leaving nodes than the static networks where there is no extra communication for the handover and authentication. The motivation of this research work is to investigate and propose new algorithms not only to improve the efficiency of these existing authentication and key management schemes in terms of connectivity, memory and security by considering the mobility scenario in wireless sensor networks, but also to develop new algorithms that suit these constrained networks than the existing schemes. First, we choose the existing key pool approach for authentication and key management and improve its network connectivity and resilience against some well known attacks (e.g. node capturing attacks) while reduce the memory cost by storing those key pools in each sensor node. In the proposed solution, we have divided the main key pool into two virtual mutually exclusive key pools. This division and constructing a key from two chosen keys, one from each key pool, helps to reduce the memory cost of each node by assigning fewer keys for the same level of network connectivity as the existing key pool frameworks. Although, the proposed key pool approach increases the network resilience against node compromission attacks because of the smaller number of keys assigned to each node, however it does not completely nullify the effect of the attacks. Hence we proposed an online mutual authentication and key establishment and management scheme for sensor networks that provides almost 100\% network connectivity and also nullifies the effect of node compromission attacks. In the proposed online key generation approach, the secret key is dependent on both communicating parties. Once the two communicating parties authenticate each other, they would successfully establish a secret communication key, otherwise they stop communication and inform the network manager about the intruder detection and activity. The last part of the thesis considers the integration of two different technologies (i.e. wireless sensor networks and IP networks). This is a very interesting and demanding research area because of its numerous applications, such as smart energy, smart city etc.. However the security requirements of these two kind of networks (resource constrained and resourceful) make key management a challenging task. Hence we use an online key generation approach using elliptic curve cryptography which gives the same security level as the standard PKI approach used in IP networks with smaller key length and is suited for the sensor network packet size limitations. It also uses a less computationally expensive approach than PKI and hence makes ECC suitable to be adopted in wireless sensor networks. In the key management scheme for IP based sensor networks, we generate the public private key pair based on ECC for each individual sensor node. However the public key is not only dependent on the node's parameter but also the parameters of the network to which it belongs. This increases the security of the proposed solution and avoids intruders pretending to be authentic members of the network(s) by spreading their own public keys. In the last part of the thesis we consider Content Centric Networking (CCN) which is a new routing architecture for the internet of the future. Building on the observation that today's communications are more oriented towards content retrieval (web, P2P, etc.) than point-to-point communications (VoIP, IM, etc.), CCN proposes a radical revision of the Internet architecture switching from named hosts (TCP/IP protocols) to named data to best match its current usage. In a nutshell, content is addressable, routable, self-sufficient and authenticated, while locations no longer matter. Data is seen and identified directly by a routable name instead of a location (the address of the server). Consequently, data is directly requested at the network level not from its holder, hence there is no need for the DNS). To improve content diffusion, CCN relies on data distribution and duplication, because storage is cheaper than bandwidth: every content - particularly popular one - can be replicated and stored on any CCN node, even untrustworthy. People looking for particular content can securely retrieve it in a P2P-way from the best locations available. So far, there has been little investigation of the security of CCNs and there is no specific key management scheme for that. We propose an authentication and key establishment scheme for CCNs in which the contents are authenticated by the content generating node, using pre-distributed shares of encryption keys. The content requesting node can get those shares from any node in the network, even from malicious and intruder ones, in accordance with a key concept of CCNs. In our work we also provide means to protect the distributed shares from modification by these malicious/intruder nodes. The proposed scheme is again an online key generation approach but including a relation between the content and its encryption key. This dependency prevents the attackers from modifying the packet or the key share

A Novel Architectural Framework on IoT Ecosystem, Security Aspects and Mechanisms: A Comprehensive Survey

For the past few years, the Internet of Things (IoT) technology continues to not only gain popularity and importance, but also witnesses the true realization of everything being smart. With the advent of the concept of smart everything, IoT has emerged as an area of great potential and incredible growth. An IoT ecosystem centers around innovation perspective which is considered as its fundamental core. Accordingly, IoT enabling technologies such as hardware and software platforms as well as standards become the core of the IoT ecosystem. However, any large-scale technological integration such as the IoT development poses the challenge to ensure secure data transmission. Perhaps, the ubiquitous and the resource-constrained nature of IoT devices and the sensitive and private data being generated by IoT systems make them highly vulnerable to physical and cyber threats. In this paper, we re-define an IoT ecosystem from the core technologies view point. We propose a modified three layer IoT architecture by dividing the perception layer into elementary blocks based on their attributed functions. Enabling technologies, attacks and security countermeasures are classified under each layer of the proposed architecture. Additionally, to give the readers a broader perspective of the research area, we discuss the role of various state-of-the-art emerging technologies in the IoT security. We present the security aspects of the most prominent standards and other recently developed technologies for IoT which might have the potential to form the yet undefined IoT architecture. Among the technologies presented in this article, we give a special interest to one recent technology in IoT domain. This technology is named IQRF that stands for Intelligent Connectivity using Radio Frequency. It is an emerging technology for wireless packet-oriented communication that operates in sub-GHz ISM band (868 MHz) and which is intended for general use where wireless connectivity is needed, either in a mesh network or point-to-point (P2P) configuration. We also highlighted the security aspects implemented in this technology and we compare it with the other already known technologies. Moreover, a detailed discussion on the possible attacks is presented. These attacks are projected on the IoT technologies presented in this article including IQRF. In addition, lightweight security solutions, implemented in these technologies, to counter these threats in the proposed IoT ecosystem architecture are also presented. Lastly, we summarize the survey by listing out some common challenges and the future research directions in this field.publishedVersio

Energy Saving Mechanisms in the Security of the Internet of Things

Energy consumption is one of the priorities of security on the Internet of Things. It is not easy to find the best solutions that will reduce energy consumption, while ensuring that the security requirements are met. Many of the issues that have been presented so far have covered the basics of security, such as the basic principles of encryption, extension environments, target applications, and so on.This paper examines one of the most effective energy-efficiency mechanisms for providing Internet-based security services. By studying techniques that enable the development of advanced energy-efficient security solutions, we take a closer look at the ideas that have already been introduced in this area. In this study, not only the security issues, but also the energy impacts on solutions have been considered. Initially, the amount of energy related to security services is introduced. Then a classification is proposed for energy efficient mechanisms on the Internet of Things. Finally, the main drivers of the impact of energy saving techniques are analyzed for security solutions

Efficient Cryptographic Algorithms and Protocols for Mobile Ad Hoc Networks

As the next evolutionary step in digital communication systems, mobile ad hoc networks (MANETs) and their specialization like wireless sensor networks (WSNs) have been attracting much interest in both research and industry communities. In MANETs, network nodes can come together and form a network without depending on any pre-existing infrastructure and human intervention. Unfortunately, the salient characteristics of MANETs, in particular the absence of infrastructure and the constrained resources of mobile devices, present enormous challenges when designing security mechanisms in this environment. Without necessary measures, wireless communications are easy to be intercepted and activities of users can be easily traced. This thesis presents our solutions for two important aspects of securing MANETs, namely efficient key management protocols and fast implementations of cryptographic primitives on constrained devices. Due to the tight cost and constrained resources of high-volume mobile devices used in MANETs, it is desirable to employ lightweight and specialized cryptographic primitives for many security applications. Motivated by the design of the well-known Enigma machine, we present a novel ultra-lightweight cryptographic algorithm, referred to as Hummingbird, for resource-constrained devices. Hummingbird can provide the designed security with small block size and is resistant to the most common attacks such as linear and differential cryptanalysis. Furthermore, we also present efficient software implementations of Hummingbird on 4-, 8- and 16-bit microcontrollers from Atmel and Texas Instruments as well as efficient hardware implementations on the low-cost field programmable gate arrays (FPGAs) from Xilinx, respectively. Our experimental results show that after a system initialization phase Hummingbird can achieve up to 147 and 4.7 times faster throughput for a size-optimized and a speed-optimized software implementation, respectively, when compared to the state-of-the-art ultra-lightweight block cipher PRESENT on the similar platforms. In addition, the speed optimized Hummingbird encryption core can achieve a throughput of 160.4 Mbps and the area optimized encryption core only occupies 253 slices on a Spartan-3 XC3S200 FPGA device. Bilinear pairings on the Jacobians of (hyper-)elliptic curves have received considerable attention as a building block for constructing cryptographic schemes in MANETs with new and novel properties. Motivated by the work of Scott, we investigate how to use efficiently computable automorphisms to speed up pairing computations on two families of non-supersingular genus 2 hyperelliptic curves over prime fields. Our findings lead to new variants of Miller's algorithm in which the length of the main loop can be up to 4 times shorter than that of the original Miller's algorithm in the best case. We also generalize Chatterjee et al.'s idea of encapsulating the computation of the line function with the group operations to genus 2 hyperelliptic curves, and derive new explicit formulae for the group operations in projective and new coordinates in the context of pairing computations. Efficient software implementation of computing the Tate pairing on both a supersingular and a non-supersingular genus 2 curve with the same embedding degree of k = 4 is investigated. Combining the new algorithm with known optimization techniques, we show that pairing computations on non-supersingular genus 2 curves over prime fields use up to 55.8% fewer field operations and run about 10% faster than supersingular genus 2 curves for the same security level. As an important part of a key management mechanism, efficient key revocation protocol, which revokes the cryptographic keys of malicious nodes and isolates them from the network, is crucial for the security and robustness of MANETs. We propose a novel self-organized key revocation scheme for MANETs based on the Dirichlet multinomial model and identity-based cryptography. Firmly rooted in statistics, our key revocation scheme provides a theoretically sound basis for nodes analyzing and predicting peers' behavior based on their own observations and other nodes' reports. Considering the difference of malicious behaviors, we proposed to classify the nodes' behavior into three categories, namely good behavior, suspicious behavior and malicious behavior. Each node in the network keeps track of three categories of behavior and updates its knowledge about other nodes' behavior with 3-dimension Dirichlet distribution. Based on its own analysis, each node is able to protect itself from malicious attacks by either revoking the keys of the nodes with malicious behavior or ceasing the communication with the nodes showing suspicious behavior for some time. The attack-resistant properties of the resulting scheme against false accusation attacks launched by independent and collusive adversaries are also analyzed through extensive simulations. In WSNs, broadcast authentication is a crucial security mechanism that allows a multitude of legitimate users to join in and disseminate messages into the networks in a dynamic and authenticated way. During the past few years, several public-key based multi-user broadcast authentication schemes have been proposed in the literature to achieve immediate authentication and to address the security vulnerability intrinsic to μTESLA-like schemes. Unfortunately, the relatively slow signature verification in signature-based broadcast authentication has also incurred a series of problems such as high energy consumption and long verification delay. We propose an efficient technique to accelerate the signature verification in WSNs through the cooperation among sensor nodes. By allowing some sensor nodes to release the intermediate computation results to their neighbors during the signature verification, a large number of sensor nodes can accelerate their signature verification process significantly. When applying our faster signature verification technique to the broadcast authentication in a 4×4 grid-based WSN, a quantitative performance analysis shows that our scheme needs 17.7%~34.5% less energy and runs about 50% faster than the traditional signature verification method

Cryptography, Dependability and Privacy in Decentralized Systems

Decentralized systems are distributed systems that disperse computation tasks to multiple parties without relying on a trusted central authority. Since any party can be attacked and compromised by malicious adversaries, ensuring security becomes a major concern in decentralized systems. Depending on the model of decentralized systems, different computation tasks leverage cryptography and secure protocols to protect their security and obtain dependable outputs. In this dissertation, we examine prior security solutions and study the inherent difficulties of securely performing computation tasks in decentralized systems by focusing on three complementary components. – We evaluate the performance of cryptographic algorithms in decentralized systems where nodes may have different amounts of computing resources. We provide a benchmark of widely deployed cryptographic algorithms on devices with a different extent of resource constraints, and show what computing capabilities are required for a device to perform expensive cryptographic operations. – We investigate the dependability issue in individual decentralized systems, where parties are not allowed to communicate with each other. We show that even if some parties are compromised or malicious, the entire decentralized system can still converge to a dependable result. – We address the privacy concern in collaborative decentralized systems, where parties need to share information with each other. We show that parties can collaborate with each other and obtain a dependable result without revealing any useful information about their privacy