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J. Areitio, L. Martínez, J. Lopez, and J. A. Montenegro, "Análisis, Diseño e Implementación de un Entorno Escalable de Comercio-e con Seguridad Telemática Adaptable Basada en PKI",
I Simposio Español de Comercio Electrónico (SEC’01), pp. 145-160, Octubre, 2001. More..

Abstract

La presente ponencia aborda el desarrollo de un entorno seguro escalable para el Comercio Electrónico. Se ha tratado la cuestión en dos fases: primero, idear un prototipo generalizado distribuido seguro formado por diferentes entidades genéricas con el objetivo de permitir que los clientes realicen sus compras y transacciones bancarias con un nivel de seguridad escalable; y en segundo lugar, implantar en la práctica un prototipo de grado de escalabilidad reducido como modelo empírico.

J. Areitio, and J. Lopez, "Mecanismo de Seguridad de Bajo Costo para Micropagos",
VI Reunion Española de Criptología y Seguridad de la Información (VI RECSI), pp. 193-200, Septiembre, 2000. More..

Abstract

La presente comunicación presenta un mecanismo de micropagos flexible, de bajo costo que puede utilizarse para realizar pagos en línea entre el cliente y el vendedor y fuera de línea con el agente de negocios. Este mecanismo evita grandes almacenamientos de datos y cálculos largos. Se puede implantar en software para el cliente y en hardware/software para el vendedor.  

PDF icon JavierAreitio2000a.pdf (63.72 KB)
C. Alcaraz, E. Etcheves Miciolino, and S. Wolthusen, "Multi-Round Attacks on Structural Controllability Properties for Non-Complete Random Graphs",
The 16th Information Security Conference (ISC), vol. 7807, Springer, pp. 140–151, 09/2015. DOI More..

Abstract

 The notion of controllability, informally the ability to force a system into a desired state in a finite time or number of steps, is most closely associated with control systems such as those used to maintain power networks and other critical infrastructures, but has wider relevance in distributed systems. It is clearly highly desirable to understand under which conditions attackers may be able to disrupt legitimate control, or to force overriding controllability themselves. Following recent results by Liu et al., there has been considerable interest also in graph-theoretical interpretation of Kalman controllability originally introduced by Lin, structural controllability. This permits the identification of sets of driver nodes with the desired state-forcing property, but determining such nodes is aW[2]-hard problem. To extract these nodes and represent the control relation, here we apply the POWER DOMINATING SET problem and investigate the effects of targeted iterative multiple-vertex removal. We report the impact that different attack strategies with multiple edge and vertex removal will have, based on underlying non-complete graphs, with an emphasis on power-law random graphs with different degree sequences.

PDF icon alcaraz2013controla.pdf (169.18 KB)
C. Alcaraz, J. Lopez, and K-K. Raymond Choo, "Dynamic Restoration in Interconnected RBAC-based Cyber-Physical Control Systems",
Proceedings of the 13th International Joint Conference on e-Business and Telecommunications (SECRYPT 2016), pp. 19-27, 2016. DOI More..

Abstract

Increasingly, automatic restoration is an indispensable security measure in control systems (e.g. those used in critical infrastructure sectors) due to the importance of ensuring the functionality of monitoring infrastructures. Modernizing the interconnection of control systems to provide interoperability between different networks, at a low cost, is also a critical requirement in control systems. However, automated recovery mechanisms are currently costly, and ensuring interoperability particularly at a low cost remains a topic of scientific challenge. This is the gap we seek to address in this paper. More specifically, we propose a restoration model for interconnected contexts, taking into account the theory of supernode and structural controllability, as well as the recommendations given by the IEC-62351-8 standard (which are mainly based on the implementation of a role-based access control system).

PDF icon 1585.pdf (2.17 MB)
C. Alcaraz, P. Najera, J. Lopez, and R. Roman, "Wireless Sensor Networks and the Internet of Things: Do We Need a Complete Integration?",
1st International Workshop on the Security of the Internet of Things (SecIoT’10), IEEE, pp. xxxx, December, 2010. More..

Abstract

Wireless sensor networks (WSN) behave as a digital skin, providing a virtual layer where the information about the physical world can be accessed by any computational system. As a result, they are an invaluable resource for realizing the vision of the Internet of Things (IoT). However, it is necessary to consider whether the devices of a WSN should be completely integrated into the Internet or not. In this paper, we tackle this question from the perspective of security. While we will mention the different security challenges that may arise in such integration process, we will focus on the issues that take place at the network level.

PDF icon calcaraz10.pdf (343.96 KB)
C. Alcaraz, I. Agudo, D. Nuñez, and J. Lopez, "Managing Incidents in Smart Grids à la Cloud",
IEEE CloudCom 2011, IEEE Computer Society, pp. 527-531, Nov-Dec 2011. DOI More..

Abstract

During the last decade, the Cloud Computing paradigm has emerged as a panacea for many problems in traditional IT infrastructures. Much has been said about the potential of Cloud Computing in the Smart Grid context, but unfortunately it is still relegated to a second layer when it comes to critical systems. Although the advantages of outsourcing those kind of applications to the cloud is clear, data confidentiality and operational privacy stand as mayor drawbacks. In this paper, we try to give some hints on which security mechanisms and more specific, which cryptographic schemes, will help a better integration of Smart Grids and Clouds. We propose the use of Virtual SCADA in the Cloud (VS-Cloud) as a mean to improve reliability and efficiency whilst maintaining the same protection level as in traditional SCADA architectures.

 

PDF icon 1643.pdf (272.71 KB)
C. Alcaraz, A. Balastegui, and J. Lopez, "Early Warning System for Cascading Effect Control in Energy Control Systems",
5th International conference on Critical Information Infrastructures Security (CRITIS’10), LNCS 6712, Springer, pp. 55-67, September, 2010. More..

Abstract

A way of controlling a cascading effect caused by a failure or a threat in a critical system is using intelligent mechanisms capable of predicting anomalous behaviours and also capable of reacting against them in advance. These mechanisms are known as Early Warning Systems (EWS) and this will be precisely the main topic of this paper. Specially, we present an EWS design based on a Wireless Sensor Network (using the ISA100.11a standard) that constantly supervise the application context. This EWS is also based on forensic techniques to provide dynamic learning capacities. As a result, this new approach will aid to provide a reliable control of incidences by offering a dynamic alarm management, identification of the most suitable field operator to attend an alarm, reporting of causes and responsible operators, and learning from new anomalous situations.

PDF icon Alcaraz2010b.pdf (5.6 MB)
C. Alcaraz, and J. Lopez, "Addressing Situational Awareness in Critical Domains of a Smart Grid",
6th International Conference on Network and System Security (NSS 2012), LNCS 7645 7645, Springer-Verlag, pp. 58-71, November 2012. DOI More..

Abstract

Control and situational awareness are two very important aspects within critical control systems, since potential faults or anomalous behaviors could lead to serious consequences by hiding the real status of supervised critical infrastructures. Examples of these infrastructures are energy generation, transmission or distribution systems that belong to Smart Grid systems. Given the importance of these systems for social welfare and its economy, a situational awareness-based model, composed of a set of current technologies, is proposed in this paper. The model focuses on addressing and offering a set of minimum services for protection, such as prevention, detection, response, self-evaluation and maintenance, thereby providing a desirable protection in unplanned situations.

 

PDF icon 1729.pdf (518.81 KB)
C. Alcaraz, R. Roman, and J. Lopez, "Análisis de la Aplicabilidad de las Redes de Sensores para la Protección de Infraestructuras de Información Críticas",
VI Jornadas de Ingeniería Telemática (JITEL’08), pp. 437, September, 2008. More..

Abstract

Las infraestructuras críticas, como el sector energético, la banca, el transporte, y muchas otras, son un pilar esencial para en bienestar de la sociedad y la economía de un país. Estas infraestructuras dependen a su vez de ciertas infraestructuras de información, las cuales permiten su correcto funcionamiento. La tarea de proteger esas infraestructuras (de información) críticas es compleja y multidimensional, con una gran cantidad de desafíos por resolver. Precisamente, las redes de sensores pueden ser de gran ayuda para esta tarea, debido a suscapacidades de control distribuidas y a su habilidad de funcionar en situaciones extremas. Este artículo analiza la utilidad de las redes de sensores en este contexto, describiendo tanto sus capacidades como sus posibles roles y mecanismos de integración para la protección de infraestructuras (de información) críticas.

PDF icon Alcaraz2008.pdf (87.41 KB)
C. Alcaraz, and R. Roman, "Applying Key Infrastructures for Sensor Networks in CIP/CIIP Scenarios",
1st International Workshop on Critical Information Infrastructures Security (CRITIS’06), LNCS 4347, Springer Berlin / Heidelberg, pp. 166-178, 2006. DOI More..

Abstract

It is commonly agreed that Wireless Sensor Networks (WSN) is one of the technologies that better fulfills features like the ones required by Critical (Information) Infrastructures. However, a sensor network is highly vulnerable against any external or internal attacks, thus network designers must know which are the tools that they can use in order to avoid such problems. In this paper we describe in detail a procedure (the KMS Guidelines), developed under our CRISIS project, that allows network designers to choose a certain Key Management System, or at least to know which protocol need to improve in order to satisfy the network requirements.

PDF icon Alcaraz2006.pdf (150.66 KB)
C. Alcaraz, L. Cazorla, and G. Fernandez, "Context-Awareness using Anomaly-based Detectors for Smart Grid Domains",
9th International Conference on Risks and Security of Internet and Systems , vol. 8924, Springer International Publishing, pp. 17-34, 04/2015. DOI More..

Abstract

Anomaly-based detection applied in strongly interdependent systems, like Smart Grids, has become one of the most challenging research areas in recent years. Early detection of anomalies so as to detect and prevent unexpected faults or stealthy threats is attracting a great deal of attention from the scientific community because it offers potential solutions for context-awareness. These solutions can also help explain the conditions leading up to a given situation and help determine the degree of its severity. However, not all the existing approaches within the literature are equally effective in covering the needs of a particular scenario. It is necessary to explore the control requirements of the domains that comprise a Smart Grid, identify, and even select, those approaches according to these requirements and the intrinsic conditions related to the application context, such as technological heterogeneity and complexity. Therefore, this paper analyses the functional features of existing anomaly-based approaches so as to adapt them, according to the aforementioned conditions. The result of this investigation is a guideline for the construction of preventive solutions that will help improve the context-awareness in the control of Smart Grid domains in the near future.

PDF icon 931.pdf (134.49 KB)
C. Alcaraz, R. Roman, and J. Lopez, "Análisis de primitivas criptográficas para redes de sensores",
VI Jornadas de Ingeniería Telemática (JITEL’07), pp. 401-408, September, 2007. More..

Abstract

Security in wireless sensor networks is very limited due to highly-constrained hardware of sensor nodes. To protect services is necessary to use secure foundations, known as security primitives, like part of a protocol. Theses primitives must assure at least confidentiality in the communication channel, authentication of the peers involved in an information exchange, and integrity of the messages. There are many primitives such as symmetric encryption, hash functions and public key cryptography, but not all of them can be supported by sensor nodes since require high resource levels, for example memory. This paper contains a deep analysis of available and suitable security primitives for sensor nodes, as well as an analysis of hardware and software implementations. Besides, it has been developed an experiment with two implementations, and it has been created a new and improved version using the optimizations of each.

PDF icon Alcaraz2007.pdf (205.14 KB)
C. Alcaraz, E. Etcheves Miciolino, and S. Wolthusen, "Structural Controllability of Networks for Non-Interactive Adversarial Vertex Removal",
8th International Conference on Critical Information Infrastructures Security, vol. 8328, Springer, pp. 120-132, 2013. DOI More..

Abstract

The problem of controllability of networks arises in a number of different domains, including in critical infrastructure systems where control must be maintained continuously. Recent work by Liu et al. has renewed interest in the seminal work by Lin on structural controllability, providing a graph-theoretical interpretation. This allows the identification of driver nodes capable of forcing the system into a desired state, which implies an obvious target for attackers wishing to disrupt the network control. Several methods for identifying driver nodes exist, but require undesirable computational complexity. In this paper, we therefore investigate the ability to regain or maintain controllability in the presence of adversaries able to remove vertices and implicit edges of the controllability graph. For this we rely on the POWER DOMINATING SET (PDS) formulation for identifying the control structure and study different attack strategies for multiple network models. As the construction of a PDS for a given graph is not unique, we further investigate different strategies for PDS construction, and provide a simulative evaluation.

PDF icon 1810.pdf (625.81 KB)
C. Alcaraz, J. Rodriguez, R. Roman, and J. E. Rubio, "Estado y Evolución de la Detección de Intrusiones en los Sistemas Industriales",
III Jornadas Nacionales de Investigación en Ciberseguridad (JNIC 2017), 2017. More..

Abstract

Debido a la necesidad de proteger los sistemas industriales ante amenazas, se hace necesario comprender cual es el verdadero alcance de los mecanismos capaces de detectar potenciales anomalías e intrusiones. Es por tanto el objetivo de este artículo analizar el estado y la evolución, tanto académica como industrial, de los mecanismos de detección de intrusiones en este campo, así como estudiar su aplicabilidad actual y futura.

PDF icon 1653.pdf (271.14 KB)
C. Alcaraz, and S. Wolthusen, "Recovery of Structural Controllability for Control Systems",
Eighth IFIP WG 11.10 International Conference on Critical Infrastructure Protection, SRI International, Arlington, Virginia, USA , vol. 441, Springer, pp. 47-63, 2014. DOI More..

Abstract

Fundamental problems in control systems theory are controllability and observability, and designing control systems so that these properties are satisfied or approximated sufficiently. However, it is prudent to as- sume that an attacker will not only be able to subvert measurements but also control the system. Moreover, an advanced adversary with an understanding of the control system may seek to take over control of the entire system or parts thereof, or deny the legitimate operator this capability. The effectiveness of such attacks has been demonstrated in previous work. Indeed, these attacks cannot be ruled out given the likely existence of unknown vulnerabilities, increasing connectivity of nominally air-gapped systems and supply chain issues. The ability to rapidly recover control after an attack has been initiated and to detect an adversary’s presence is, therefore, critical. This paper focuses on the problem of structural controllability, which has recently attracted substantial attention through the equivalent problem of the power dom- inating set introduced in the context of electrical power network control. However, these problems are known to be NP-hard with poor approx- imability. Given their relevance to many networks, especially power networks, this paper studies strategies for the efficient restoration of controllability following attacks and attacker-defender interactions in power-law networks. 

PDF icon 430.pdf (418.49 KB)
C. Alcaraz, R. Roman, P. Najera, and J. Lopez, "Acceso seguro a redes de sensores en SCADA a través de Internet",
XI Reunión Española sobre Criptología y Seguridad de la Información (RECSI 2010), pp. 337-342, September, 2010. More..

Abstract

Las Infraestructuras Críticas (ICs) son monitorizadas por sistemas altamente complejos, conocidos como sistemas SCADA (Sistemas de Control y Adquisición de Datos), cuyo principal soporte se encuentra en las subestaciones, las cuales miden de primera instancia el estado real de tales ICs. Para mejorar este control, la industria está actualmente demandando la integración en el modelo tradicional de dos avances tecnológicos: Internet y las redes de sensores inalámbricas. Sin embargo, su incorporación requiere analizar los requisitos de seguridad que surgen en dicho contexto, así como diversos aspectos correlacionados (ej. mantenimiento, rendimiento, seguridad y optimización) y, en base a estos, la estrategia de integración más adecuada para satisfacer dichos requisitos. Este artículo proporciona dicho análisis en profundidad con el fin de ofrecer un modelo de integración seguro adecuado para entornos críticos.

PDF icon Alcaraz2010.pdf (496.18 KB)
C. Alcaraz, and M. Sonmez, "PDR: A Prevention, Detection and Response Mechanism for Anomalies in Energy Control Systems",
7th International Conference on Critical Information Infrastructures Security (CRITIS 2012), vol. 7722, pp. 22–33, 2013. More..

Abstract

 Prevention, detection and response are nowadays considered to be three priority topics for protecting critical infrastructures, such as energy control systems. Despite attempts to address these current issues, there is still a particular lack of investigation in these areas, and in particular in dynamic and automatic proactive solutions. In this paper we propose a mechanism, which is called PDR, with the capability of anticipating anomalies, detecting anomalous behaviours and responding to them in a timely manner. PDR is based on a conglomeration of technologies and on a set of essential components with the purpose of offering situational awareness irrespective of where the system is located. In addition, the mechanism can also compute its functional capacities by evaluating its efficacy and precision in the prediction and detection of disturbances. With this, the entire system is able to know the real reliability of its services and its activity in remote substations at all times.

PDF icon alcaraz2011critis.pdf (553.41 KB)
C. Alcaraz, and J. Lopez, "Safeguarding Structural Controllability in Cyber-Physical Control Systems",
The 21st European Symposium on Research in Computer Security (ESORICS 2016), vol. 9879, Springer, pp. 471-489, 2016. More..

Abstract

Automatic restoration of control wireless networks based on dynamic cyber-physical systems has become a hot topic in recent years, since most of their elements tend to have serious vulnerabilities that may be exploited by attackers. In fact, any exploitation may rapidly extend to the entire control network due to its problem of non-locality, where control properties of a system and its structural controllability can disintegrate over time. Unfortunately, automated self-healing processes may become costly procedures in which the reliability of the strategies and the time-critical of any recovery of the control can become key factors to re-establish the control properties in due time. This operational need is precisely the aim of this paper, in which four reachability-based recovery strategies from a thereotical point of view are proposed so as to find the best option/s in terms of optimization, robustness and complexity. To do this, new definitions related to structural controllability in relation to the type of distribution of the network and its control load capacity are given in this paper, resulting in an interesting practical study.

PDF icon 1598.pdf (606.93 KB)
C. Alcaraz, et al., "Adaptive Dispatching of Incidences Based on Reputation for SCADA Systems",
6th International Conference on Trust, Privacy and Security in Digital Business (TrustBus’09), Springer-Verlag, pp. 86-94, September, 2009. DOI More..

Abstract

SCADA systems represent a challenging scenario where the management of critical alarms is crucial. Their response to these alarms should be efficient and fast in order to mitigate or contain undesired effects. This work presents a mechanism, the Adaptive Assignment Manager (AAM) that will aid to react to incidences in a more efficient way by dynamically assigning alarms to the most suitable human operator. The mechanism uses various inputs for identifying the operators such as their availability, workload and reputation. In fact, we also define a reputation component that stores the reputation of the human operators and uses feedback from past experiences.

PDF icon Alcaraz2009.pdf (289.68 KB)
I. Agudo, J. Lopez, and J. A. Montenegro, "A Representation Model of Trust Relationships with Delegation Extensions",
3th International Conference on Trust Management (iTRUST’05), LNCS 3477, Springer, pp. 9-22, May, 2005. DOI More..

Abstract

Logic languages establish a formal framework to solve authorization and delegation conflicts. However, we consider that a visual representation is necessary since graphs are more expressive and understandable than logic languages. In this paper, and after overviewing previous works using logic languages, we present a proposal for graph representation of authorization and delegation statements. Our proposal is based on Varadharajan et al. solution, though improve several elements of that work. We also discuss about the possible implementation of our proposal using attribute certificates.

PDF icon IsaacAgudo2005b.pdf (251.54 KB)
I. Agudo, J. Lopez, and J. A. Montenegro, "Implementation aspects of a delegation system",
3rd international conference on Mobile multimedia communications (MobiMedia ’07), ICST, pp. 50:1–50:6, 2007. More..

Abstract

In this paper we simulate an authorization and delegation system using knowledge based technology. This proposal is part of a visual tool that is intended to be an implementation of the theoretical model weighted trust graph (WTG). A brief description of WTG Model and its associated tool is included in the text. In essence, the model is based on the inclusion of real numbers between zero and one in certificates to represent the trust level between the entities involved in them. This trust level is used to control delegation. Moreover, attributes from di_erent domains may be interrelated, so attribute delegation is also taken into account. The proposed Simulation Engine supports one directional and bidirectional search algorithms.

PDF icon Agudo2007.pdf (193.04 KB)
I. Agudo, C. Fernandez-Gago, and J. Lopez, "An Evolutionary Trust and Distrust Model",
4th Workshop on Security and Trust Management (STM’08), ENTCS 224, Elsevier, pp. 3-12, 2008. DOI More..

Abstract

In this paper we propose a trust model, where besides considering trust and distrust, we also consider another parameter that measures the reliability on the stability of trust or distrust. The inclusion of this new parameter will allow us to use trust in a more accurate way. We consider trust is not static but dynamic and trust values can change along time. Thus, we will also take time into account, using it as a parameter of our model. There is very little work done about the inclusion of time as an influence on trust. We will show the applicability of our model in the scenario of the process of reviewing papers for a conference. Sometimes for these kind of processes the Chair of the conference should first find the suitable reviewers. He can make this selection by using our model. Once the reviewers are selected they send out their reviews to the Chair who can also use our model in order to make the final decision about acceptance of papers.

PDF icon Agudo2008b.pdf (129.8 KB)
I. Agudo, J. Lopez, and J. A. Montenegro, "Graphical Representation of Authorization Policies for Weighted Credentials",
11th Australasian Conference on Information Security and Privacy (ACISP’06), LNCS 4058, Springer, pp. 383-394, 2006. DOI More..

Abstract

This paper elaborates on a solution to represent authorization and delegation in a graphical way, allowing users to better interpret delegation relationships. We make use of Weighted Trust Graph (WTG) as an instrument to represent delegation and authorization, extending it to cope with more complicated concepts, and providing a graphical representation of the level of confidence that exists between two entities regarding a resource or attribute. We represent the level of confidence for each pair of entities as a point in an axis diagram, as a set of points, or as a set of triangular regions depending on the accuracy we need. Then, we use the same diagram to represent the set of acceptable confidence level, that we call authorization policy set. In this way, a single diagram can be used to decide about authorization, thus providing a powerful tool for systems in which interaction of users is needed.

PDF icon Agudo2006a.pdf (263.9 KB)
I. Agudo, A. El Kaafarani, D. Nuñez, and S. Pearson, "A Technique for Enhanced Provision of Appropriate Access to Evidence across Service Provision Chains",
10th International IFIP Summer School on Privacy and Identity Management, pp. 187-204, 2016. DOI More..

Abstract

Transparency and verifiability are necessary aspects of accountability, but care needs to be taken that auditing is done in a privacy friendly way. There are situations where it would be useful for certain actors to be able to make restricted views within service provision chains on accountability evidence, including logs, available to other actors with specific governance roles. For example, a data subject or a Data Protection Authority (DPA) might want to authorize an accountability agent to act on their behalf, and be given access to certain logs in a way that does not compromise the privacy of other actors or the security of involved data processors. In this paper two cryptographic-based techniques that may address this issue are proposed and assessed.

I. Agudo, J. Lopez, and J. A. Montenegro, "Attribute delegation in ubiquitous environments",
3rd international conference on Mobile multimedia communications (MobiMedia ’07), ICST, pp. 43:1–43:6, 2007. More..

Abstract

When delegation is implemented using the attribute certificates in a Privilege Management Infrastructure (PMI), this one reaches a considerable level of distributed functionality. However, the approach is not flexible enough for the requirements of ubiquitous environments. Additionally, the PMI can become a too complex solution for devices such as smartphones and PDAs, where resources are limited. In this work, we solve the previous limitations by defining a second class of attributes, called domain attributes, which are managed directly by users and are not right under the scope of the PMI, thus providing a light solution for constrained devices. The two classes of attributes are related by defining a simple ontology. We also introduce in the paper the concept of Attribute Federation which is responsible for supporting domain attributes and the corresponding ontology.

PDF icon Agudo2007a.pdf (903.72 KB)
I. Agudo, and J. Lopez, "Specification and formal verification of security requirements",
5th international conference on Computer systems and technologies (CompSysTech ’04), ACM, pp. 1-6, 2004. DOI More..

Abstract

With the grown of internet and distributed applications, security requirements are going inherent to the software development process. Each time one communicates with some other one there are relevant security risk that must be taken in account. This is what is happening in the new soft-ware applications using client/server architecture. We propose including security requirements at the top level of development process, together with functional requirements because they are much related. With this information we are able to extract all communication protocols that are involved in our application and their associated security goals. This is the input to a verification phase in which we look for security flaws. The last step, and the more useful (and the not yet finished) is to use this information to modify our initial specification at the top level of the development process

I. Agudo, J. A. Onieva, and D. Merida, "Distribución segura de componentes software basada en OpenID",
XI Reunión Española sobre Criptología y Seguridad de la Información (RECSI 2010), September, 2010. More..

Abstract

En la actualidad, cada vez son más frecuentes los ataques software mediante la utilización de malware o sustitución de programas (o componentes) en los repositorios a los cuales los usuarios finales (o máquinas) acceden. Esta situación se ve de alguna manera acentuada con el dinamismo existente en la programación y ejecución de estos componentes, en la que distintos desarrolladores pueden participar para desplegar un determinado servicio o parte de él. Por ello, en este artículo se presenta una solución para la distribución de código de forma segura usando OpenID y firmas con certificados de clave pública de corta duración. De esta forma, se consigue un compromiso de seguridad que permite distribuir código firmado sin la necesidad de que los desarrolladores dispongan a priori de un certificado específico. Presentamos además algunos detalles acerca de la implementación realizada para hacer realidad este diseño.

PDF icon Agudo2010.pdf (932.46 KB)
I. Agudo, R. Rios, and A. Nieto, "Personalized Computer Security Tasks with Automatic Evaluation and Feedback",
International Conference on Information Systems Education and Research (AIS SIGED 2019), 12/2019. More..
PDF icon 1835.pdf (590.14 KB)
I. Agudo, J. Lopez, and J. J. Ortega, "Especificación formal y verificación de requisitos de Seguridad",
VIII Reunión Española sobre Criptología y Seguridad de la Información (VIII RECSI), pp. 225-235, Sep 2004.
I. Agudo, C. Fernandez-Gago, and J. Lopez, "A Multidimensional Reputation Scheme for Identity Federations",
Sixth European Workshop on Public Key Services, Applications and Infrastructures (EuroPKI’09), LNCS 6391, Springer, pp. 225-238, 2009. DOI More..

Abstract

Deciding who to trust in the internet of services paradigm is an important and open question. How to do it in an optimal way is not always easy to determine. Trust is usually referred to a particular context whereas a single user may interact in more than one given context. We are interested in investigating how a Federated Reputation System can help exporting trust perceptions from one context to another. We propose a model for deriving trust in online services. In this context, trust is defined as the level of confidence that the service provider holds on the subject interacting with it to behave in a proper way while using the service. Thus, we derive trust by using the reputation values that those users have gained for interacting with these services.

PDF icon Agudo2009a.pdf (238.71 KB)
I. Agudo, J. Lopez, and J. A. Montenegro, "Attributes Delegation Based on Ontologies and Context Information",
10th IFIP TC-6 TC-11 International Conference on Communications and Multimedia on Security (CMS’06), LNCS 4237, Springer, pp. 54-66, October, 2006. DOI More..

Abstract

This paper presents a model for delegation based on partial orders, proposing the subclass relation in OWL as a way to represent the partial orders. Delegation and authorization decisions are made based on the context. In order to interact with the context, we define the Type of a credential as a way to introduce extra information regarding context constraints. When reasoning about delegation and authorization relationships, our model benefits from partial orders, defining them over entities, attributes and the credential type. Using these partial orders, the number of credentials required is reduced. It also classifies the possible criteria for making authorization decisions based on the context, in relation to the necessary information.

PDF icon IsaacAgudo2006.pdf (165.46 KB)
I. Agudo, C. Fernandez-Gago, and J. Lopez, "Delegating Privileges over Finite Resources: A Quota Based Delegation Approach",
5th International Workshop on Formal Aspects in Security and Trust (FAST’08), LNCS 5491, Springer, pp. 302-315, 2008. DOI More..

Abstract

When delegation in real world scenarios is considered, the delegator (the entity that posses the privileges) usually passes the privileges on to the delegatee (the entity that receives the privileges) in such a way that the former looses these privileges while the delegation is effective. If we think of a physical key that opens a door, the privilege being delegated by the owner of the key is opening the door. Once the owner of the key delegates this privilege to another entity, by handing over the key, he is not able to open the door any longer. This is due to the fact that the key is not copied and handed over but handed over to the delegatee. When delegation takes place in the electronic world, the delegator usually retains also the privileges. Thus, both users have them simultaneously. This situation, which in most cases is not a problem, may be undesirable when dealing with certain kind of resources. In particular, if we think of finite resources, those in which the number of users accessing simultaneously is finite, we can not allow that a user delegating his access privilege is also granted access when the delegation if effective. In this paper we propose an approach where each user is delegated an access quota for a resource. If further delegating of the delegated quota occurs, this is subtracted from his quota. That is, when delegating, part of the quota remains with the delegator and another part goes to the delegatee. This allows a more fairly access to the resource. Moreover, we show that this approach can also be applied to any kind of resources by defining appropriate authorization policies.

PDF icon Agudo2008.pdf (304.18 KB)
I. Agudo, J. Lopez, J. A. Montenegro, E. Okamoto, and E. Dawson, "Delegation Perspective of Practical Authorization Schemes",
Fifth International Network Conference (INC’05), pp. 157-164, 2005. More..
PDF icon IsaacAgudo2005a.pdf (64.72 KB)
I. Agudo, J. Lopez, and J. A. Montenegro, "Políticas de delegación para credenciales ponderadas y su representación gráfica",
IX Reunión Española sobre Criptología y Seguridad de la información (RECSI’06), pp. 311-322, Septiembre, 2006. More..
PDF icon IsaacAgudo2006a.pdf (574.78 KB)
I. Agudo, D. Nuñez, G. Giammatteo, P. Rizomiliotis, and C. Lambrinoudakis, "Cryptography Goes to the Cloud",
1st International Workshop on Security and Trust for Applications in Virtualised Environments (STAVE 2011), C. Lee, J-M. Seigneur, J. J. Park, and R. R. Wagner Eds., Communications in Computer and Information Science 187, Springer, pp. 190-197, June, 2011. DOI More..

Abstract

In this paper we identify some areas where cryptography can help a rapid adoption of cloud computing. Although secure storage has already captured the attention of many cloud providers, offering a higher level of protection for their customer’s data, we think that more advanced techniques such as searchable encryption and secure outsourced computation will become popular in the near future, opening the doors of the Cloud to customers with higher security requirements.

PDF icon agudo2011cryptography.pdf (122.42 KB)
I. Agudo, C. Fernandez-Gago, and J. Lopez, "A Model for Trust Metrics Analysis",
5th International Conference on Trust, Privacy and Security in Digital Business (TrustBus’08), LNCS 5185, Springer, pp. 28-37, 2008. DOI More..

Abstract

Trust is an important factor in any kind of network essential, for example, in the decision-making process. As important as the definition of trust is the way to compute it. In this paper we propose a model for defining trust based on graph theory and show examples of some simple operators and functions that will allow us to compute trust.

PDF icon Agudo2008a.pdf (129.8 KB)
A. Acien, A. Nieto, G. Fernandez, and J. Lopez, "A comprehensive methodology for deploying IoT honeypots",
15th International Conference on Trust, Privacy and Security in Digital Business (TrustBus 2018), vol. LNCS 11033, Springer Nature Switzerland AG, pp. 229–243, 09/2018. DOI More..

Abstract

Recent news have raised concern regarding the security on the IoT field. Vulnerabilities in devices are arising and honeypots are an excellent way to cope with this problem. In this work, current solutions for honeypots in the IoT context, and other solutions adaptable to it are analyzed in order to set the basis for a methodology that allows deployment of IoT honeypot.

PDF icon 1701.pdf (676.29 KB)
A. Acien, A. Nieto, and J. Lopez, "Modelo para la clasificación y análisis de ataques Cross-Platform",
IV Jornadas Nacionales de Investigación en Ciberseguridad (JNIC 2018), Servicio Editorial de Mondragon Unibertsitatea, 06/2018. More..

Abstract

Los ataques cross-platform suponen un serio desafío para los mecanismos de seguridad cuando los portadores de un ataque dirigido no son conscientes de su participacion en el mismo. Es por ello que, con dispositivos y tecnologías cada vez mas entrelazadas, en constante comunicación, numerosos ataques pasan desapercibidos hasta que alcanzan su objetivo final. Estos nuevos escenarios hacen posible una vía de transmision a tener en cuenta, y que se debe abordar cuanto antes, ya que sus consecuencias, especialmente en el panorama de telecomunicaciones actual, podrían ser desoladoras. La rapida transmisión de estos ataques, y la dificultad que supone su prevencion, detección y mitigación antes de que se hagan efectivos, hacen que el problema sea particularmente preocupante. En este artículo se presentará una arquitectura para el analisis de los ataques cross-platform silenciosos, cuyo objetivo es ayudar a comprender mejor este tipo de amenazas y ofrecer soluciones que permitan mitigarlas y rastrearlas.

PDF icon 1699.pdf (880.31 KB)
A. Acien, A. Nieto, and J. Lopez, "Analyzing cross-platform attacks: towards a three-actor approach",
The 16th IEEE International Conference on Dependable, Autonomic and Secure Computing (DASC 2018), pp. 536-543, 08/2018. DOI More..

Abstract

In the current telecommunications landscape, different devices, systems and platforms are constantly communicating with each other. This heterogeneous environment creates the perfect situation for attacks to pass from one platform to another. This is a particularly worrying scenario, because of the new technologies being used (such as network slicing in 5G), the increasing importance of connected devices in our lives (IoT), and the unpredictable consequences that an attack of this type could have. The current approaches in attack analysis do not take into account these sitations, and the attacker/victim paradigm usually followed may fall short when dealing with these attacks. Thus, in this paper, an architecture for the analysis of cross-platform attacks will be presented, aiming to help understand better this kind of threats and offering solutions to mitigate and track them.
 

PDF icon 1709.pdf (650.37 KB)
A. Acien, A. Nieto, G. Fernandez, and J. Lopez, "Definición de procedimientos para fabricar honeypots IoT basados en criterios de búsqueda",
XV Reunión Española sobre Criptología y Seguridad de la Información, 10/2018. More..

Abstract

Con la revolución tecnológica que ha supuesto la Internet de las Cosas (Internet of Things, IoT) se han presentado escenarios donde la preocupación por la seguridad en dicho entorno es cada vez más relevante. Están comenzando a surgir vulnerabilidades en varios dispositivos, y los sistemas trampa son una excelente manera de lidiar con este problema. En este trabajo se analizan soluciones para honeypots en el entorno IoT (y en otros que se puedan adaptar) para sentar las bases de una metodología que permita el despliegue de honeypots IoT.

PDF icon 1706.pdf (1.16 MB)