Building Realistic Mobility Models for Mobile Ad Hoc Networks

A mobile ad hoc network (MANET) is a self-configuring wireless network in which each node could act as a router, as well as a data source or sink. Its application areas include battlefields and vehicular and disaster areas. Many techniques applied to infrastructure-based networks are less effective in MANETs, with routing being a particular challenge. This paper presents a rigorous study into simulation techniques for evaluating routing solutions for MANETs with the aim of producing more realistic simulation models and thereby, more accurate protocol evaluations. MANET simulations require models that reflect the world in which the MANET is to operate. Much of the published research uses movement models, such as the random waypoint (RWP) model, with arbitrary world sizes and node counts. This paper presents a technique for developing more realistic simulation models to test and evaluate MANET protocols. The technique is animation, which is applied to a realistic scenario to produce a model that accurately reflects the size and shape of the world, node count, movement patterns, and time period over which the MANET may operate. The animation technique has been used to develop a battlefield model based on established military tactics. Trace data has been used to build a model of maritime movements in the Irish Sea. Similar world models have been built using the random waypoint movement model for comparison. All models have been built using the ns-2 simulator. These models have been used to compare the performance of three routing protocols: dynamic source routing (DSR), destination-sequenced distance-vector routing (DSDV), and ad hoc n-demand distance vector routing (AODV). The findings reveal that protocol performance is dependent on the model used. In particular, it is shown that RWP models do not reflect the performance of these protocols under realistic circumstances, and protocol selection is subject to the scenario to which it is applied. To conclude, it is possible to develop a range of techniques for modelling scenarios applicable to MANETs, and these simulation models could be utilised for the evaluation of routing protocols

Protocolos para la seguridad de la información en eHealth: Criptografía en entornos mHeath

Abstract. The advance of technology has brought with it the evolution of tools in various fields, among which the medical field stands out. Today’s medicine has tools that 30 years ago were unthinkable making its functioning completely different. Thanks to this fusion of medicine and technology new terms concerning this symbiosis, such as eHealth or mHealth, may be found in our daily lives. Both users and all the areas that work in the protection and performance of health and safety benefit from it. In this doctoral thesis we have worked in several lines with the aim of improving information security in several mHealth systems trying to make the proposed solutions extrapolable to other environments. Firstly, a tool, supported by an expert system and using identity-based encryption for the protection of patient information, for the diagnosis, treatment and monitoring of children with attention deficit disorder is proposed. Second, a solution focused on geared towards enhancing solutions for two of the fundamental problems of medical data information security: the secure management of patient information and the identification of patients within the hospital environment, is included. The solution proposed for the identification problem is based on the use of NFC bracelets that store an identifier associated with the patient and is generated through an HMAC function. In the third work, the problem of identification is again analyzed, but this time in emergency environments where no stable communication networks are present. It also proposes a system for the classification of victims whose objective is to improve the management of health resources in these scenarios. The fourth contribution is a system for improving the traceability and management of small emergencies and everyday events based on the use of blockchains. To conclude with the contributions of this thesis, a cryptographic scheme which improves security in healthcare devices with little computing capacity is presented. The general aim of this thesis is providing improvements in current medicine through mHealth systems, paying special attention to information security. Specifically, measures for the protection of data integrity, identification, authentication and nonrepudiation of information are included. The completion of this doctoral thesis has been funded through a pre-doctoral FPI grant from the Canary Islands Government.El avance de la tecnología ha traído consigo la evolución de herramientas en diversos ámbitos, entre ellos destaca el de la medicina. La medicina actual posee unas herramientas que hace 30 años eran impensables, lo que hace que su funcionamiento sea completamente diferente. Gracias a esta fusión de medicina y tecnología encontramos en nuestro día a día nuevos términos, como eHealth o mHealth, que hacen referencia a esta simbiosis, en la que se benefician tanto los usuarios, como todas las áreas que trabajan en la protección y actuación de la salud y seguridad de las mismas. En esta tesis doctoral se ha trabajado en varias líneas con el objetivo de mejorar la seguridad de la información en varios sistemas mHealth intentando que las soluciones propuestas sean extrapolables a otros entornos. En primer lugar se propone una herramienta destinada al diagnóstico, tratamiento y monitorización de niños con trastorno de déficit de atención que se apoya en un sistema experto y usa cifrado basado en identidad para la protección de la información de los pacientes. En segundo lugar, se incluye una solución centrada en aportar mejoras en dos de los problemas fundamentales de la seguridad de la información de los datos médicos: la gestión segura de la información de los pacientes y la identificación de los mismos dentro del entorno hospitalario. La solución planteada para el problema de identificación se basa en la utilización de pulseras NFC que almacenan un identificador asociado al paciente y que es generado a través de una función HMAC. En el tercer trabajo se analiza de nuevo el problema de identificación de las personas pero esta vez en entornos de emergencia en los que no se cuenta con redes de comunicaciones estables. Además se propone un sistema de clasificación de víctimas en dichos entornos cuyo objetivo es mejorar la gestión de recursos sanitarios en estos escenarios. Como cuarta aportación se presenta un sistema de mejora de la trazabilidad y de la gestión de pequeñas emergencias y eventos cotidianos basada en el uso de blockchain. Para terminar con las aportaciones de esta tesis, se presenta un esquema criptográfico que mejora los esquemas actuales de seguridad utilizados para dispositivos del entorno sanitario que poseen poca capacidad computacional. La finalidad general perseguida en esta tesis es aportar mejoras al uso de la medicina actual a través de sistemas mHealth en los que se presta especial atención a la seguridad de la información. Concretamente se incluyen medidas para la protección de la integridad de los datos, identificación de personas, autenticación y no repudio de la información. La realización de esta tesis doctoral ha contando con financiación del Gobierno de Canarias a través de una beca predoctoral FPI