Security architecture for Fog-To-Cloud continuum system

Nowadays, by increasing the number of connected devices to Internet rapidly, cloud computing cannot handle the real-time processing. Therefore, fog computing was emerged for providing data processing, filtering, aggregating, storing, network, and computing closer to the users. Fog computing provides real-time processing with lower latency than cloud. However, fog computing did not come to compete with cloud, it comes to complete the cloud. Therefore, a hierarchical Fog-to-Cloud (F2C) continuum system was introduced. The F2C system brings the collaboration between distributed fogs and centralized cloud. In F2C systems, one of the main challenges is security. Traditional cloud as security provider is not suitable for the F2C system due to be a single-point-of-failure; and even the increasing number of devices at the edge of the network brings scalability issues. Furthermore, traditional cloud security cannot be applied to the fog devices due to their lower computational power than cloud. On the other hand, considering fog nodes as security providers for the edge of the network brings Quality of Service (QoS) issues due to huge fog device’s computational power consumption by security algorithms. There are some security solutions for fog computing but they are not considering the hierarchical fog to cloud characteristics that can cause a no-secure collaboration between fog and cloud. In this thesis, the security considerations, attacks, challenges, requirements, and existing solutions are deeply analyzed and reviewed. And finally, a decoupled security architecture is proposed to provide the demanded security in hierarchical and distributed fashion with less impact on the QoS.Hoy en día, al aumentar rápidamente el número de dispositivos conectados a Internet, el cloud computing no puede gestionar el procesamiento en tiempo real. Por lo tanto, la informática de niebla surgió para proporcionar procesamiento de datos, filtrado, agregación, almacenamiento, red y computación más cercana a los usuarios. La computación nebulizada proporciona procesamiento en tiempo real con menor latencia que la nube. Sin embargo, la informática de niebla no llegó a competir con la nube, sino que viene a completar la nube. Por lo tanto, se introdujo un sistema continuo jerárquico de niebla a nube (F2C). El sistema F2C aporta la colaboración entre las nieblas distribuidas y la nube centralizada. En los sistemas F2C, uno de los principales retos es la seguridad. La nube tradicional como proveedor de seguridad no es adecuada para el sistema F2C debido a que se trata de un único punto de fallo; e incluso el creciente número de dispositivos en el borde de la red trae consigo problemas de escalabilidad. Además, la seguridad tradicional de la nube no se puede aplicar a los dispositivos de niebla debido a su menor poder computacional que la nube. Por otro lado, considerar los nodos de niebla como proveedores de seguridad para el borde de la red trae problemas de Calidad de Servicio (QoS) debido al enorme consumo de energía computacional del dispositivo de niebla por parte de los algoritmos de seguridad. Existen algunas soluciones de seguridad para la informática de niebla, pero no están considerando las características de niebla a nube jerárquica que pueden causar una colaboración insegura entre niebla y nube. En esta tesis, las consideraciones de seguridad, los ataques, los desafíos, los requisitos y las soluciones existentes se analizan y revisan en profundidad. Y finalmente, se propone una arquitectura de seguridad desacoplada para proporcionar la seguridad exigida de forma jerárquica y distribuida con menor impacto en la QoS.Postprint (published version

Game theory analysis and modeling of sophisticated multi-collusion attack in MANETs

Mobile Adhoc Network (MANET) has been a core topic of research since the last decade. Currently, this form of networking paradigm is increasingly being construed as an integral part of upcoming urban applications of Internet-of-Things (IoT), consisting of massive connectivity of diverse types of nodes. There is a significant barrier to the applicability of existing routing approaches in conventional MANETs when integrated with IoT. This routing mismatch can lead to security risks for the MANET-based application tied with the IoT platform. This paper examines a pragmatic scenario as a test case wherein the mobile nodes must exchange multimedia signals for supporting real-time streaming applications. There exist two essential security requirements viz. i) securing the data packet and ii) understanding the unpredictable behavior of the attacker. The current study considers sophistication on the part of attacker nodes. They are aware of each other’s identity and thereby collude to conduct lethal attacks, which is rarely reflected in existing security modeling statistics. This research harnesses the potential modeling aspect of game theory to model the multiple-collusion attacker scenario. It contributes towards i) modeling strategies of regular/malicious nodes and ii) applying optimization principle using novel auxiliary information to formulate the optimal strategies. The model advances each regular node’s capability to carry out precise computation about the opponent player’s strategy prediction, i.e., malicious node. The simulation outcome of the proposed mathematical model in MATLAB ascertains that it outperforms the game theory’s baseline approach

Maritime expressions:a corpus based exploration of maritime metaphors

This study uses a purpose-built corpus to explore the linguistic legacy of Britain’s maritime history found in the form of hundreds of specialised ‘Maritime Expressions’ (MEs), such as TAKEN ABACK, ANCHOR and ALOOF, that permeate modern English. Selecting just those expressions commencing with ’A’, it analyses 61 MEs in detail and describes the processes by which these technical expressions, from a highly specialised occupational discourse community, have made their way into modern English. The Maritime Text Corpus (MTC) comprises 8.8 million words, encompassing a range of text types and registers, selected to provide a cross-section of ‘maritime’ writing. It is analysed using WordSmith analytical software (Scott, 2010), with the 100 million-word British National Corpus (BNC) as a reference corpus. Using the MTC, a list of keywords of specific salience within the maritime discourse has been compiled and, using frequency data, concordances and collocations, these MEs are described in detail and their use and form in the MTC and the BNC is compared. The study examines the transformation from ME to figurative use in the general discourse, in terms of form and metaphoricity. MEs are classified according to their metaphorical strength and their transference from maritime usage into new registers and domains such as those of business, politics, sports and reportage etc. A revised model of metaphoricity is developed and a new category of figurative expression, the ‘resonator’, is proposed. Additionally, developing the work of Lakov and Johnson, Kovesces and others on Conceptual Metaphor Theory (CMT), a number of Maritime Conceptual Metaphors are identified and their cultural significance is discussed