Resilience of the Internet of Things (IoT) from an Information Assurance (IA) Perspective

Internet infrastructure developments and the rise of the IoT Socio-Technical Systems (STS) have frequently generated more unsecure protocols to facilitate the rapid intercommunication between the plethoras of IoT devices. Whereas, current development of the IoT has been mainly focused on enabling and effectively meeting the functionality requirement of digital-enabled enterprises we have seen scant regard to their IA architecture, marginalizing system resilience with blatant afterthoughts to cyber defence. Whilst interconnected IoT devices do facilitate and expand information sharing; they further increase of risk exposure and potential loss of trust to their Socio-Technical Systems. A change in the IoT paradigm is needed to enable a security-first mind-set; if the trusted sharing of information built upon dependable resilient growth of IoT is to be established and maintained. We argue that Information Assurance is paramount to the success of IoT, specifically its resilience and dependability to continue its safe support for our digital economy

CYBER SECURITY @ HOME: The Effect of Home User Perceptions of Personal Security Performance on Household IoT Security Intentions

This study explored potential human factors predictors of home user security intentions through the lens of past performance, perceived self-efficacy, and locus of control. While perceived self-efficacy and locus of control are elements in several organizational and individual security models, past performance has been less frequently studied. The variable, past performance, which has been referred to in other studies as prior experience, knowledge, and information security awareness, is usually a single question self-assessment of familiarity or comfort with technology. This study explores user technical prowess in further depth, using formal technical education, informal technical education, employment in an IT/CS field, and self-reported email and internet security measures as a measurement of technical ability. Security intentions were determined by best practices in hardware security, network security, and IoT device protection. Studying IoT security in home users is important because there are 26.6 billion devices connected to the Internet already, with 127 devices are being added to the network every second, which creates a very large attack surface if left unsecured. Unlike organizations, with dedicated IT departments, home users must provide their own security within their network. Instead of building security around the user, this research attempts to determine what human factors variables effect intentions to use existing security technologies. Through an online survey, home users provided information on their background, device usage, perceived ability to perform security behaviors, level of control over their environment, current security intentions, and future security intentions. Hierarchical linear regression, path modeling, and structural equation modeling determined that past performance was consistently the strongest predictor of security intentions for home users. Self-efficacy and locus of control had varying results among the disparate methods. Additionally, exposure to security concepts through the survey had an effect on user security intentions, as measured at the end of the survey. This research contributed an initial model for the effects of past performance, self-efficacy, and locus of control on security intentions. It provided verification for existing self-efficacy and locus of control measurements, as well as comprehensive, modular security intentions survey questions. Additionally, this study provided insight into the effect of demographics on security intentions

Survey and Systematization of Secure Device Pairing

Secure Device Pairing (SDP) schemes have been developed to facilitate secure communications among smart devices, both personal mobile devices and Internet of Things (IoT) devices. Comparison and assessment of SDP schemes is troublesome, because each scheme makes different assumptions about out-of-band channels and adversary models, and are driven by their particular use-cases. A conceptual model that facilitates meaningful comparison among SDP schemes is missing. We provide such a model. In this article, we survey and analyze a wide range of SDP schemes that are described in the literature, including a number that have been adopted as standards. A system model and consistent terminology for SDP schemes are built on the foundation of this survey, which are then used to classify existing SDP schemes into a taxonomy that, for the first time, enables their meaningful comparison and analysis.The existing SDP schemes are analyzed using this model, revealing common systemic security weaknesses among the surveyed SDP schemes that should become priority areas for future SDP research, such as improving the integration of privacy requirements into the design of SDP schemes. Our results allow SDP scheme designers to create schemes that are more easily comparable with one another, and to assist the prevention of persisting the weaknesses common to the current generation of SDP schemes.Comment: 34 pages, 5 figures, 3 tables, accepted at IEEE Communications Surveys & Tutorials 2017 (Volume: PP, Issue: 99

Orchestration of distributed ingestion and processing of IoT data for fog platforms

In recent years there has been an extraordinary growth of the Internet of Things (IoT) and its protocols. The increasing diffusion of electronic devices with identification, computing and communication capabilities is laying ground for the emergence of a highly distributed service and networking environment. The above mentioned situation implies that there is an increasing demand for advanced IoT data management and processing platforms. Such platforms require support for multiple protocols at the edge for extended connectivity with the objects, but also need to exhibit uniform internal data organization and advanced data processing capabilities to fulfill the demands of the application and services that consume IoT data. One of the initial approaches to address this demand is the integration between IoT and the Cloud computing paradigm. There are many benefits of integrating IoT with Cloud computing. The IoT generates massive amounts of data, and Cloud computing provides a pathway for that data to travel to its destination. But today’s Cloud computing models do not quite fit for the volume, variety, and velocity of data that the IoT generates. Among the new technologies emerging around the Internet of Things to provide a new whole scenario, the Fog Computing paradigm has become the most relevant. Fog computing was introduced a few years ago in response to challenges posed by many IoT applications, including requirements such as very low latency, real-time operation, large geo-distribution, and mobility. Also this low latency, geo-distributed and mobility environments are covered by the network architecture MEC (Mobile Edge Computing) that provides an IT service environment and Cloud-computing capabilities at the edge of the mobile network, within the Radio Access Network (RAN) and in close proximity to mobile subscribers. Fog computing addresses use cases with requirements far beyond Cloud-only solution capabilities. The interplay between Cloud and Fog computing is crucial for the evolution of the so-called IoT, but the reach and specification of such interplay is an open problem. This thesis aims to find the right techniques and design decisions to build a scalable distributed system for the IoT under the Fog Computing paradigm to ingest and process data. The final goal is to explore the trade-offs and challenges in the design of a solution from Edge to Cloud to address opportunities that current and future technologies will bring in an integrated way. This thesis describes an architectural approach that addresses some of the technical challenges behind the convergence between IoT, Cloud and Fog with special focus on bridging the gap between Cloud and Fog. To that end, new models and techniques are introduced in order to explore solutions for IoT environments. This thesis contributes to the architectural proposals for IoT ingestion and data processing by 1) proposing the characterization of a platform for hosting IoT workloads in the Cloud providing multi-tenant data stream processing capabilities, the interfaces over an advanced data-centric technology, including the building of a state-of-the-art infrastructure to evaluate the performance and to validate the proposed solution. 2) studying an architectural approach following the Fog paradigm that addresses some of the technical challenges found in the first contribution. The idea is to study an extension of the model that addresses some of the central challenges behind the converge of Fog and IoT. 3) Design a distributed and scalable platform to perform IoT operations in a moving data environment. The idea after study data processing in Cloud, and after study the convenience of the Fog paradigm to solve the IoT close to the Edge challenges, is to define the protocols, the interfaces and the data management to solve the ingestion and processing of data in a distributed and orchestrated manner for the Fog Computing paradigm for IoT in a moving data environment.En els últims anys hi ha hagut un gran creixement del Internet of Things (IoT) i els seus protocols. La creixent difusió de dispositius electrònics amb capacitats d'identificació, computació i comunicació esta establint les bases de l’aparició de serveis altament distribuïts i del seu entorn de xarxa. L’esmentada situació implica que hi ha una creixent demanda de plataformes de processament i gestió avançada de dades per IoT. Aquestes plataformes requereixen suport per a múltiples protocols al Edge per connectivitat amb el objectes, però també necessiten d’una organització de dades interna i capacitats avançades de processament de dades per satisfer les demandes de les aplicacions i els serveis que consumeixen dades IoT. Una de les aproximacions inicials per abordar aquesta demanda és la integració entre IoT i el paradigma del Cloud computing. Hi ha molts avantatges d'integrar IoT amb el Cloud. IoT genera quantitats massives de dades i el Cloud proporciona una via perquè aquestes dades viatgin a la seva destinació. Però els models actuals del Cloud no s'ajusten del tot al volum, varietat i velocitat de les dades que genera l'IoT. Entre les noves tecnologies que sorgeixen al voltant del IoT per proporcionar un escenari nou, el paradigma del Fog Computing s'ha convertit en la més rellevant. Fog Computing es va introduir fa uns anys com a resposta als desafiaments que plantegen moltes aplicacions IoT, incloent requisits com baixa latència, operacions en temps real, distribució geogràfica extensa i mobilitat. També aquest entorn està cobert per l'arquitectura de xarxa MEC (Mobile Edge Computing) que proporciona serveis de TI i capacitats Cloud al edge per la xarxa mòbil dins la Radio Access Network (RAN) i a prop dels subscriptors mòbils. El Fog aborda casos d?us amb requisits que van més enllà de les capacitats de solucions només Cloud. La interacció entre Cloud i Fog és crucial per a l'evolució de l'anomenat IoT, però l'abast i especificació d'aquesta interacció és un problema obert. Aquesta tesi té com objectiu trobar les decisions de disseny i les tècniques adequades per construir un sistema distribuït escalable per IoT sota el paradigma del Fog Computing per a ingerir i processar dades. L'objectiu final és explorar els avantatges/desavantatges i els desafiaments en el disseny d'una solució des del Edge al Cloud per abordar les oportunitats que les tecnologies actuals i futures portaran d'una manera integrada. Aquesta tesi descriu un enfocament arquitectònic que aborda alguns dels reptes tècnics que hi ha darrere de la convergència entre IoT, Cloud i Fog amb especial atenció a reduir la bretxa entre el Cloud i el Fog. Amb aquesta finalitat, s'introdueixen nous models i tècniques per explorar solucions per entorns IoT. Aquesta tesi contribueix a les propostes arquitectòniques per a la ingesta i el processament de dades IoT mitjançant 1) proposant la caracterització d'una plataforma per a l'allotjament de workloads IoT en el Cloud que proporcioni capacitats de processament de flux de dades multi-tenant, les interfícies a través d'una tecnologia centrada en dades incloent la construcció d'una infraestructura avançada per avaluar el rendiment i validar la solució proposada. 2) estudiar un enfocament arquitectònic seguint el paradigma Fog que aborda alguns dels reptes tècnics que es troben en la primera contribució. La idea és estudiar una extensió del model que abordi alguns dels reptes centrals que hi ha darrere de la convergència de Fog i IoT. 3) Dissenyar una plataforma distribuïda i escalable per a realitzar operacions IoT en un entorn de dades en moviment. La idea després d'estudiar el processament de dades a Cloud, i després d'estudiar la conveniència del paradigma Fog per resoldre el IoT prop dels desafiaments Edge, és definir els protocols, les interfícies i la gestió de dades per resoldre la ingestió i processament de dades en un distribuït i orquestrat per al paradigma Fog Computing per a l'IoT en un entorn de dades en moviment

The Digital Agricultural Revolution: a Bibliometric Analysis Literature Review

The application of digital technologies in agriculture can improve traditional practices to adapt to climate change, reduce Greenhouse Gases (GHG) emissions, and promote a sustainable intensification for food security. Some authors argued that we are experiencing a Digital Agricultural Revolution (DAR) that will boost sustainable farming. This study aims to find evidence of the ongoing DAR process and clarify its roots, what it means, and where it is heading. We investigated the scientific literature with bibliometric analysis tools to produce an objective and reproducible literature review. We retrieved 4995 articles by querying the Web of Science database in the timespan 2012-2019, and we analyzed the obtained dataset to answer three specific research questions: i) what is the spectrum of the DAR-related terminology?; ii) what are the key articles and the most influential journals, institutions, and countries?; iii) what are the main research streams and the emerging topics? By grouping the authors' keywords reported on publications, we identified five main research streams: Climate-Smart Agriculture (CSA), Site-Specific Management (SSM), Remote Sensing (RS), Internet of Things (IoT), and Artificial Intelligence (AI). To provide a broad overview of each of these topics, we analyzed relevant review articles, and we present here the main achievements and the ongoing challenges. Finally, we showed the trending topics of the last three years (2017, 2018, 2019)

INVESTIGATION OF INDUSTRY 5.0 HURDLES AND THEIR MITIGATION TACTICS IN EMERGING ECONOMIES BY TODIM ARITHMETIC AND GEOMETRIC AGGREGATION OPERATORS IN SINGLE VALUE NEUTROSOPHIC ENVIRONMENT

Industry 5.0 acceptance is accelerating, but research is still in its infancy, and existing research covers a small subset of context-specific obstacles. This study aims to enumerate all potential obstacles, quantitatively rank them, and assess interdependencies at the organizational level for Industry 5.0 adoption. To achieve this, we thoroughly review the literature, identify obstacles, and investigate causal relationships using a multi-criteria decision-making approach called single value Neutrosophic TODIM. Single-valued Neutrosophic sets (SVNS) ensembles are employed in a real-world setting to deal with uncertainty and indeterminacy. The suggested strategy enables the experts to conduct group decision-making by focusing on ranking the smaller collection of criterion values and the comparison with the decision-making trial and evaluation laboratory method (DEMATEL). According to the findings, the most significant hurdles are expenses and the funding system, capacity scalability, upskilling, and reskilling of human labor. As a result, a comfortable atmosphere is produced for decision-making, enabling the experts to handle an acceptable amount of data while still making choices

Expressive policy based authorization model for resource-constrained device sensors.

Los capítulos II, III y IV están sujetos a confidencialidad por el autor 92 p.Upcoming smart scenarios enabled by the Internet of Things (IoT) envision smart objects that expose services that can adapt to user behavior or be managed with the goal of achieving higher productivity, often in multistakeholder applications. In such environments, smart things are cheap sensors (and actuators) and, therefore, constrained devices. However, they are also critical components because of the importance of the provided information. Given that, strong security in general and access control in particular is a must.However, tightness, feasibility and usability of existing access control models do not cope well with the principle of least privilege; they lack both expressiveness and the ability to update the policy to be enforced in the sensors. In fact, (1) traditional access control solutions are not feasible in all constrained devices due their big impact on the performance although they provide the highest effectiveness by means of tightness and flexibility. (2) Recent access control solutions designed for constrained devices can be implemented only in not so constrained ones and lack policy expressiveness in the local authorization enforcement. (3) Access control solutions currently feasible in the most severely constrained devices have been based on authentication and very coarse grained and static policies, scale badly, and lack a feasible policy based access control solution aware of local context of sensors.Therefore, there is a need for a suitable End-to-End (E2E) access control model to provide fine grained authorization services in service oriented open scenarios, where operation and management access is by nature dynamic and that integrate massively deployed constrained but manageable sensors. Precisely, the main contribution of this thesis is the specification of such a highly expressive E2E access control model suitable for all sensors including the most severely constrained ones. Concretely, the proposed E2E access control model consists of three main foundations. (1) A hybrid architecture, which combines advantages of both centralized and distributed architectures to enable multi-step authorization. Fine granularity of the enforcement is enabled by (2) an efficient policy language and codification, which are specifically defined to gain expressiveness in the authorization policies and to ensure viability in very-constrained devices. The policy language definition enables both to make granting decisions based on local context conditions, and to react accordingly to the requests by the execution of additional tasks defined as obligations.The policy evaluation and enforcement is performed not only during the security association establishment but also afterward, while such security association is in use. Moreover, this novel model provides also control over access behavior, since iterative re-evaluation of the policy is enabled during each individual resource access.Finally, (3) the establishment of an E2E security association between two mutually authenticated peers through a security protocol named Hidra. Such Hidra protocol, based on symmetric key cryptography, relies on the hybrid three-party architecture to enable multi-step authorization as well as the instant provisioning of a dynamic security policy in the sensors. Hidra also enables delegated accounting and audit trail. Proposed access control features cope with tightness, feasibility and both dimensions of usability such as scalability and manageability, which are the key unsolved challenges in the foreseen open and dynamic scenarios enabled by IoT. Related to efficiency, the high compression factor of the proposed policy codification and the optimized Hidra security protocol relying on a symmetric cryptographic schema enable the feasibility as it is demonstrated by the validation assessment. Specifically, the security evaluation and both the analytical and experimental performance evaluation demonstrate the feasibility and adequacy of the proposed protocol and access control model.Concretely, the security validation consists of the assessment that the Hidra security protocol meets the security goals of mutual strong authentication, fine-grained authorization, confidentiality and integrity of secret data and accounting. The security analysis of Hidra conveys on the one hand, how the design aspects of the message exchange contribute to the resilience against potential attacks. On the other hand, a formal security validation supported by a software tool named AVISPA ensures the absence of flaws and the correctness of the design of Hidra.The performance validation is based on an analytical performance evaluation and a test-bed implementation of the proposed access control model for the most severely constrained devices. The key performance factor is the length of the policy instance, since it impacts proportionally on the three critical parameters such as the delay, energy consumption, memory footprint and therefore, on the feasibility.Attending to the obtained performance measures, it can be concluded that the proposed policy language keeps such balance since it enables expressive policy instances but always under limited length values. Additionally, the proposed policy codification improves notably the performance of the protocol since it results in the best policy length compression factor compared with currently existing and adopted standards.Therefore, the assessed access control model is the first approach to bring to severely constrained devices a similar expressiveness level for enforcement and accounting as in current Internet. The positive performance evaluation concludes the feasibility and suitability of this access control model, which notably rises the security features on severely constrained devices for the incoming smart scenarios.Additionally, there is no comparable impact assessment of policy expressiveness of any other access control model. That is, the presented analysis models as well as results might be a reference for further analysis and benchmarkingGaur egun darabilzkigun hainbeste gailutan mikroprozesadoreak daude txertatuta, eragiten duten prozesuan neurketak egin eta logika baten ondorioz ekiteko. Horretarako, bai sentsoreak eta baita aktuadoreak erabiltzen dira (hemendik aurrera, komunitatean onartuta dagoenez, sentsoreak esango diegu nahiz eta erabilpen biak izan). Orain arteko erabilpen zabalenetako konekzio motak, banaka edota sare lokaletan konekatuta izan dira. Era honetan, sentsoreak elkarlanean elkarreri eraginez edota zerbitzari nagusi baten agindupean, erakunde baten prozesuak ahalbideratu eta hobetzeko erabili izan dira.Internet of Things (IoT) deritzonak, sentsoreak dituzten gailuak Internet sarearen bidez konektatu eta prozesu zabalagoak eta eraginkorragoak ahalbidetzen ditu. Smartcity, Smartgrid, Smartfactory eta bestelako smart adimendun ekosistemak, gaur egun dauden eta datozen komunikaziorako teknologien aukerak baliatuz, erabilpen berriak ahalbideratu eta eragina areagotzea dute helburu.Era honetan, ekosistema hauek zabalak dira, eremu ezberdinetako erakundeek hartzen dute parte, eta berariazko sentsoreak dituzten gailuen kopurua izugarri handia da. Sentsoreak beraz, berariazkoak, merkeak eta txikiak dira, eta orain arteko lehenengo erabilpen nagusia, magnitude fisikoren bat neurtzea eta neurketa hauek zerbitzari zentralizatu batera bidaltzea izan da. Hau da, inguruan gertatzen direnak neurtu, eta zerbitzari jakin bati neurrien datuak aldiro aldiro edota atari baten baldintzapean igorri. Zerbitzariak logika aplikatu eta sistema osoa adimendun moduan jardungo du. Jokabide honetan, aurretik ezagunak diren entitateen arteko komunikazioen segurtasuna bermatzearen kexka, nahiz eta Internetetik pasatu, hein onargarri batean ebatzita dago gaur egun.Baina adimendun ekosistema aurreratuak sentsoreengandik beste jokabide bat ere aurreikusten dute. Sentsoreek eurekin harremanak izateko moduko zerbitzuak ere eskaintzen dituzte. Erakunde baten prozesuetan, beste jatorri bateko erakundeekin elkarlanean, jokabide honen erabilpen nagusiak bi dira. Batetik, prozesuan parte hartzen duen erabiltzaileak (eta jabeak izan beharrik ez duenak) inguruarekin harremanak izan litzake, eta bere ekintzetan gailuak bere berezitasunetara egokitzearen beharrizana izan litzake. Bestetik, sentsoreen jarduera eta mantenimendua zaintzen duten teknikariek, beroriek egokitzeko zerbitzuen beharrizana izan dezakete.Holako harremanak, sentsoreen eta erabiltzaileen kokalekua zehaztugabea izanik, kasu askotan Internet bidez eta zuzenak (end-to-end) izatea aurreikusten da. Hau da, sentsore txiki asko daude handik hemendik sistemaren adimena ahalbidetuz, eta harreman zuzenetarako zerbitzu ñimiñoak eskainiz. Batetik, zerbitzu zuzena, errazagoa eta eraginkorragoa dena, bestetik erronkak ere baditu. Izan ere, sentsoreak hain txikiak izanik, ezin dituzte gaur egungo protokolo eta mekanismo estandarak gauzatu. Beraz, sare mailatik eta aplikazio mailarainoko berariazko protokoloak sortzen ari dira.Tamalez, protokolo hauek arinak izatea dute helburu eta segurtasuna ez dute behar den moduan aztertu eta gauzatzen. Eta egon badaude berariazko sarbide kontrolerako ereduak baina baliabideen urritasuna dela eta, ez dira ez zorrotzak ez kudeagarriak. Are gehiago, Gartnerren arabera, erabilpen aurreratuetan inbertsioa gaur egun mugatzen duen traba Nagusia segurtasunarekiko mesfidantza da.Eta hauxe da erronka eta tesi honek landu duen gaia: batetik sentsoreak hain txikiak izanik, eta baliabideak hain urriak (10kB RAM, 100 kB Flash eta bateriak, sentsore txikienetarikoetan), eta bestetik Internet sarea hain zabala eta arriskutsua izanik, segurtasuna areagotuko duen sarbide zuzenaren kontrolerako eredu zorrotz, arin eta kudeagarri berri bat zehaztu eta bere erabilgarritasuna aztertu

Expressive policy based authorization model for resource-constrained device sensors.

Los capítulos II, III y IV están sujetos a confidencialidad por el autor 92 p.Upcoming smart scenarios enabled by the Internet of Things (IoT) envision smart objects that expose services that can adapt to user behavior or be managed with the goal of achieving higher productivity, often in multistakeholder applications. In such environments, smart things are cheap sensors (and actuators) and, therefore, constrained devices. However, they are also critical components because of the importance of the provided information. Given that, strong security in general and access control in particular is a must.However, tightness, feasibility and usability of existing access control models do not cope well with the principle of least privilege; they lack both expressiveness and the ability to update the policy to be enforced in the sensors. In fact, (1) traditional access control solutions are not feasible in all constrained devices due their big impact on the performance although they provide the highest effectiveness by means of tightness and flexibility. (2) Recent access control solutions designed for constrained devices can be implemented only in not so constrained ones and lack policy expressiveness in the local authorization enforcement. (3) Access control solutions currently feasible in the most severely constrained devices have been based on authentication and very coarse grained and static policies, scale badly, and lack a feasible policy based access control solution aware of local context of sensors.Therefore, there is a need for a suitable End-to-End (E2E) access control model to provide fine grained authorization services in service oriented open scenarios, where operation and management access is by nature dynamic and that integrate massively deployed constrained but manageable sensors. Precisely, the main contribution of this thesis is the specification of such a highly expressive E2E access control model suitable for all sensors including the most severely constrained ones. Concretely, the proposed E2E access control model consists of three main foundations. (1) A hybrid architecture, which combines advantages of both centralized and distributed architectures to enable multi-step authorization. Fine granularity of the enforcement is enabled by (2) an efficient policy language and codification, which are specifically defined to gain expressiveness in the authorization policies and to ensure viability in very-constrained devices. The policy language definition enables both to make granting decisions based on local context conditions, and to react accordingly to the requests by the execution of additional tasks defined as obligations.The policy evaluation and enforcement is performed not only during the security association establishment but also afterward, while such security association is in use. Moreover, this novel model provides also control over access behavior, since iterative re-evaluation of the policy is enabled during each individual resource access.Finally, (3) the establishment of an E2E security association between two mutually authenticated peers through a security protocol named Hidra. Such Hidra protocol, based on symmetric key cryptography, relies on the hybrid three-party architecture to enable multi-step authorization as well as the instant provisioning of a dynamic security policy in the sensors. Hidra also enables delegated accounting and audit trail. Proposed access control features cope with tightness, feasibility and both dimensions of usability such as scalability and manageability, which are the key unsolved challenges in the foreseen open and dynamic scenarios enabled by IoT. Related to efficiency, the high compression factor of the proposed policy codification and the optimized Hidra security protocol relying on a symmetric cryptographic schema enable the feasibility as it is demonstrated by the validation assessment. Specifically, the security evaluation and both the analytical and experimental performance evaluation demonstrate the feasibility and adequacy of the proposed protocol and access control model.Concretely, the security validation consists of the assessment that the Hidra security protocol meets the security goals of mutual strong authentication, fine-grained authorization, confidentiality and integrity of secret data and accounting. The security analysis of Hidra conveys on the one hand, how the design aspects of the message exchange contribute to the resilience against potential attacks. On the other hand, a formal security validation supported by a software tool named AVISPA ensures the absence of flaws and the correctness of the design of Hidra.The performance validation is based on an analytical performance evaluation and a test-bed implementation of the proposed access control model for the most severely constrained devices. The key performance factor is the length of the policy instance, since it impacts proportionally on the three critical parameters such as the delay, energy consumption, memory footprint and therefore, on the feasibility.Attending to the obtained performance measures, it can be concluded that the proposed policy language keeps such balance since it enables expressive policy instances but always under limited length values. Additionally, the proposed policy codification improves notably the performance of the protocol since it results in the best policy length compression factor compared with currently existing and adopted standards.Therefore, the assessed access control model is the first approach to bring to severely constrained devices a similar expressiveness level for enforcement and accounting as in current Internet. The positive performance evaluation concludes the feasibility and suitability of this access control model, which notably rises the security features on severely constrained devices for the incoming smart scenarios.Additionally, there is no comparable impact assessment of policy expressiveness of any other access control model. That is, the presented analysis models as well as results might be a reference for further analysis and benchmarkingGaur egun darabilzkigun hainbeste gailutan mikroprozesadoreak daude txertatuta, eragiten duten prozesuan neurketak egin eta logika baten ondorioz ekiteko. Horretarako, bai sentsoreak eta baita aktuadoreak erabiltzen dira (hemendik aurrera, komunitatean onartuta dagoenez, sentsoreak esango diegu nahiz eta erabilpen biak izan). Orain arteko erabilpen zabalenetako konekzio motak, banaka edota sare lokaletan konekatuta izan dira. Era honetan, sentsoreak elkarlanean elkarreri eraginez edota zerbitzari nagusi baten agindupean, erakunde baten prozesuak ahalbideratu eta hobetzeko erabili izan dira.Internet of Things (IoT) deritzonak, sentsoreak dituzten gailuak Internet sarearen bidez konektatu eta prozesu zabalagoak eta eraginkorragoak ahalbidetzen ditu. Smartcity, Smartgrid, Smartfactory eta bestelako smart adimendun ekosistemak, gaur egun dauden eta datozen komunikaziorako teknologien aukerak baliatuz, erabilpen berriak ahalbideratu eta eragina areagotzea dute helburu.Era honetan, ekosistema hauek zabalak dira, eremu ezberdinetako erakundeek hartzen dute parte, eta berariazko sentsoreak dituzten gailuen kopurua izugarri handia da. Sentsoreak beraz, berariazkoak, merkeak eta txikiak dira, eta orain arteko lehenengo erabilpen nagusia, magnitude fisikoren bat neurtzea eta neurketa hauek zerbitzari zentralizatu batera bidaltzea izan da. Hau da, inguruan gertatzen direnak neurtu, eta zerbitzari jakin bati neurrien datuak aldiro aldiro edota atari baten baldintzapean igorri. Zerbitzariak logika aplikatu eta sistema osoa adimendun moduan jardungo du. Jokabide honetan, aurretik ezagunak diren entitateen arteko komunikazioen segurtasuna bermatzearen kexka, nahiz eta Internetetik pasatu, hein onargarri batean ebatzita dago gaur egun.Baina adimendun ekosistema aurreratuak sentsoreengandik beste jokabide bat ere aurreikusten dute. Sentsoreek eurekin harremanak izateko moduko zerbitzuak ere eskaintzen dituzte. Erakunde baten prozesuetan, beste jatorri bateko erakundeekin elkarlanean, jokabide honen erabilpen nagusiak bi dira. Batetik, prozesuan parte hartzen duen erabiltzaileak (eta jabeak izan beharrik ez duenak) inguruarekin harremanak izan litzake, eta bere ekintzetan gailuak bere berezitasunetara egokitzearen beharrizana izan litzake. Bestetik, sentsoreen jarduera eta mantenimendua zaintzen duten teknikariek, beroriek egokitzeko zerbitzuen beharrizana izan dezakete.Holako harremanak, sentsoreen eta erabiltzaileen kokalekua zehaztugabea izanik, kasu askotan Internet bidez eta zuzenak (end-to-end) izatea aurreikusten da. Hau da, sentsore txiki asko daude handik hemendik sistemaren adimena ahalbidetuz, eta harreman zuzenetarako zerbitzu ñimiñoak eskainiz. Batetik, zerbitzu zuzena, errazagoa eta eraginkorragoa dena, bestetik erronkak ere baditu. Izan ere, sentsoreak hain txikiak izanik, ezin dituzte gaur egungo protokolo eta mekanismo estandarak gauzatu. Beraz, sare mailatik eta aplikazio mailarainoko berariazko protokoloak sortzen ari dira.Tamalez, protokolo hauek arinak izatea dute helburu eta segurtasuna ez dute behar den moduan aztertu eta gauzatzen. Eta egon badaude berariazko sarbide kontrolerako ereduak baina baliabideen urritasuna dela eta, ez dira ez zorrotzak ez kudeagarriak. Are gehiago, Gartnerren arabera, erabilpen aurreratuetan inbertsioa gaur egun mugatzen duen traba Nagusia segurtasunarekiko mesfidantza da.Eta hauxe da erronka eta tesi honek landu duen gaia: batetik sentsoreak hain txikiak izanik, eta baliabideak hain urriak (10kB RAM, 100 kB Flash eta bateriak, sentsore txikienetarikoetan), eta bestetik Internet sarea hain zabala eta arriskutsua izanik, segurtasuna areagotuko duen sarbide zuzenaren kontrolerako eredu zorrotz, arin eta kudeagarri berri bat zehaztu eta bere erabilgarritasuna aztertu