986 research outputs found
DrAGON: A Framework for Computing Preferred Defense Policies from Logical Attack Graphs
Attack graphs provide formalism for modelling the vulnerabilities using a compact representation scheme. Two of the most popular attack graph representations are scenario attack graphs, and logical attack graphs. In logical attack graphs, the host machines present in the network are represented as exploit nodes, while the configurations (IDS rules, firewall policies etc.) running on them are represented as fact nodes. The actual user privileges that are possible on each of these hosts are represented as privilege nodes.
Existing work provides methods to analyze logical attack graphs and compute attack paths of varying costs. In this thesis we develop a framework for analyzing the attack graph from a defender perspective. Given an acyclic logical dependency attack graph we compute defense policies that cover all known exploits that can be used by the attacker and also are preferred with respect to minimizing the impacts. In contrast to previous work on analysis of logical attack graphs where quantitative costs are assigned to the vulnerabilities (exploits), our framework allows attack graph analysis using descriptions of vulnerabilities on a qualitative scale. We develop two algorithms for computing preferred defense policies that are optimal with respect to defender preferences. Our research to the best of our knowledge is the first fully qualitative approach to analyzing these logical attack graphs and formulating defense policies based on the preferences and priorities of the defender.
We provide a prototype implementation of our framework that allows logical attack graphs to be input using a simple text file (custom language), or using a GUI tool in graphical markup language (GML) format. Our implementation uses the NVD (National Vulnerability Database) as the source of CVSS impact metrics for vulnerabilities in the attack graph. Our framework generates a preferred order of defense policies using an existing preference reasoner. Preliminary experiments on various attack graphs show the correctness and efficiency of our approach
Contributions to the privacy provisioning for federated identity management platforms
Identity information, personal data and user’s profiles are key assets for organizations
and companies by becoming the use of identity management (IdM) infrastructures a prerequisite
for most companies, since IdM systems allow them to perform their business
transactions by sharing information and customizing services for several purposes in more
efficient and effective ways.
Due to the importance of the identity management paradigm, a lot of work has been done
so far resulting in a set of standards and specifications. According to them, under the
umbrella of the IdM paradigm a person’s digital identity can be shared, linked and reused
across different domains by allowing users simple session management, etc. In this way,
users’ information is widely collected and distributed to offer new added value services
and to enhance availability. Whereas these new services have a positive impact on users’
life, they also bring privacy problems.
To manage users’ personal data, while protecting their privacy, IdM systems are the ideal
target where to deploy privacy solutions, since they handle users’ attribute exchange.
Nevertheless, current IdM models and specifications do not sufficiently address comprehensive
privacy mechanisms or guidelines, which enable users to better control over the
use, divulging and revocation of their online identities. These are essential aspects, specially
in sensitive environments where incorrect and unsecured management of user’s data
may lead to attacks, privacy breaches, identity misuse or frauds.
Nowadays there are several approaches to IdM that have benefits and shortcomings, from
the privacy perspective.
In this thesis, the main goal is contributing to the privacy provisioning for federated
identity management platforms. And for this purpose, we propose a generic architecture
that extends current federation IdM systems. We have mainly focused our contributions
on health care environments, given their particularly sensitive nature. The two main
pillars of the proposed architecture, are the introduction of a selective privacy-enhanced
user profile management model and flexibility in revocation consent by incorporating an
event-based hybrid IdM approach, which enables to replace time constraints and explicit
revocation by activating and deactivating authorization rights according to events. The
combination of both models enables to deal with both online and offline scenarios, as well
as to empower the user role, by letting her to bring together identity information from
different sources.
Regarding user’s consent revocation, we propose an implicit revocation consent mechanism
based on events, that empowers a new concept, the sleepyhead credentials, which
is issued only once and would be used any time. Moreover, we integrate this concept
in IdM systems supporting a delegation protocol and we contribute with the definition
of mathematical model to determine event arrivals to the IdM system and how they are
managed to the corresponding entities, as well as its integration with the most widely
deployed specification, i.e., Security Assertion Markup Language (SAML).
In regard to user profile management, we define a privacy-awareness user profile management
model to provide efficient selective information disclosure. With this contribution a
service provider would be able to accesses the specific personal information without being
able to inspect any other details and keeping user control of her data by controlling
who can access. The structure that we consider for the user profile storage is based on
extensions of Merkle trees allowing for hash combining that would minimize the need of
individual verification of elements along a path. An algorithm for sorting the tree as we
envision frequently accessed attributes to be closer to the root (minimizing the access’
time) is also provided.
Formal validation of the above mentioned ideas has been carried out through simulations
and the development of prototypes. Besides, dissemination activities were performed in
projects, journals and conferences.Programa Oficial de Doctorado en Ingeniería TelemáticaPresidente: María Celeste Campo Vázquez.- Secretario: María Francisca Hinarejos Campos.- Vocal: Óscar Esparza Martí
Reasoning with qualitative preferences for optimization of component-based system development
A component-based system is a set of entities that work together in well-defined ways to satisfy a given requirement specified by the stakeholders for the system. This requirement can be modeled as a set of combinations of traits, which represent acceptable alternatives for providing the required functionality. A system satisfies its requirement if and only if it provides one of the required sets of traits in its entirety. Beyond the requirement, system stakeholders may also have preferences with respect to optional functionality that could be provided by a system, tradeoffs between non-functional properties, or other system design options. This work focuses on integrating support for both qualitative preference reasoning and formal verification into the component-based system design process in order to choose a set of components for the system that, when composed, will (1) satisfy the stakeholders\u27 requirement for the system and (2) provide a set of traits that is optimal with respect to the given preferences. Our primary research objective is to develop a generic, modular, end-to-end framework for developing component-based systems of any type which are correct according to the system requirement and most preferred with respect to the stakeholders\u27 preferences. Applications of the framework to problems in Web service composition, goal-oriented requirements engineering, and other areas will be discussed, along with future work toward integrating multi-stakeholder preference reasoning and partial satisfaction of traits into the framework
Optimized trusted information sharing
As the digital world expands the building of trust and the retention of privacy in information sharing becomes paramount. A major impediment to information sharing is a lack of trust between the parties, based on security and privacy concerns, as well as information asymmetry. Several technological solutions have been proposed to solve this problem, including our\u27s: a trusted enclave with a Continuous Compliance Assurance (CCA) mechanism. Of the work surrounding these proposed solutions, no attention has been directed toward studying the issues of performance surrounding processing of this nature. Studies have shown that ignoring the performance of a system can lead to ineffectiveness (i.e. disabling certain features), and can be severely detrimental to system adoption.;To ensure that our trusted enclave and CCA mechanism are viable solutions to the trusted information sharing problem, we have built a prototype CCA mechanism and a test bed. The test bed has allowed us to identify problem areas within our prototype. One such area is compliance verification, which utilizes the XPath language in order to test XML encoded information for compliance to regulatory and corporate policies. The compliance verification problem can be described as the answering of multiple queries over a single XML document. We proposed and tested multiple state-of-the-art algorithmic as well as system-based improvements to XPath evaluation, in order to better the overall performance of this aspect of our system. We integrated each of the improvements into our prototype mechanism and have observed the results. Our experiments have taught us much about the problem of compliance verification, and has led us in new directions as we continue to search for a solution
Electronic Voting: 6th International Joint Conference, E-Vote-ID 2021, Virtual Event, October 5–8, 2021: proceedings
This volume contains the papers presented at E-Vote-ID 2021, the Sixth International
Joint Conference on Electronic Voting, held during October 5–8, 2021. Due to the
extraordinary situation brought about by the COVID-19, the conference was held
online for the second consecutive edition, instead of in the traditional venue in
Bregenz, Austria. The E-Vote-ID conference is the result of the merger of the EVOTE
and Vote-ID conferences, with first EVOTE conference taking place 17 years ago in
Austria. Since that conference in 2004, over 1000 experts have attended the venue,
including scholars, practitioners, authorities, electoral managers, vendors, and PhD
students. The conference focuses on the most relevant debates on the development of
electronic voting, from aspects relating to security and usability through to practical
experiences and applications of voting systems, also including legal, social, or political
aspects, amongst others, and has turned out to be an important global referent in
relation to this issue
Sixth International Joint Conference on Electronic Voting E-Vote-ID 2021. 5-8 October 2021
This volume contains papers presented at E-Vote-ID 2021, the Sixth International Joint Conference on Electronic Voting, held during October 5-8, 2021. Due to the extraordinary situation provoked by Covid-19 Pandemic, the conference is held online for second consecutive edition, instead of in the traditional venue in Bregenz, Austria. E-Vote-ID Conference resulted from the merging of EVOTE and Vote-ID and counting up to 17 years since the _rst E-Vote conference in Austria. Since that conference in 2004, over 1000 experts have attended the venue, including scholars, practitioners, authorities, electoral managers, vendors, and PhD Students. The conference collected the most relevant debates on the development of Electronic Voting, from aspects relating to security and usability through to practical experiences and applications of voting systems, also including legal, social or political aspects, amongst others; turning out to be an important global referent in relation to this issue.
Also, this year, the conference consisted of:
· Security, Usability and Technical Issues Track
· Administrative, Legal, Political and Social Issues Track
· Election and Practical Experiences Track
· PhD Colloquium, Poster and Demo Session on the day before the conference
E-VOTE-ID 2021 received 49 submissions, being, each of them, reviewed by 3 to 5 program committee members, using a double blind review process. As a result, 27 papers were accepted for its presentation in the conference. The selected papers cover a wide range of topics connected with electronic voting, including experiences and revisions of the real uses of E-voting systems and corresponding processes in elections.
We would also like to thank the German Informatics Society (Gesellschaft für Informatik) with its ECOM working group and KASTEL for their partnership over many years. Further we would like to thank the Swiss Federal Chancellery and the Regional Government of Vorarlberg for their kind support. EVote-
ID 2021 conference is kindly supported through European Union's Horizon 2020 projects ECEPS (grant agreement 857622) and mGov4EU (grant agreement 959072). Special thanks go to the members of the international program committee for their hard work in reviewing, discussing, and shepherding papers. They ensured the high quality of these proceedings with their knowledge and experience
Lived Experiences of Beginning Counselors in Harmful Supervision
When supervision moves beyond poor oversight to inciting personal and professional impairment, it becomes harmful. Although there is much in the literature regarding ineffective supervision in general, empirical data explicating harmful supervision is significantly less available. In fact, the negative effects of harmful supervision may be notably more severe than those reported of ineffective supervision (Unger, 1995). The purpose of this study was to provide rich description and meaning of beginning counselors’ experiences in harmful supervision. The research question addressed was, “What is the lived experience of beginning counselors in harmful supervision?” Transcendental, existential phenomenology (van Manen, 2014; Thomas & Pollio, 2002) was the chosen method utilized to investigate seven participants’ subjective experiences of harmful supervision during their mental health practicum and/or internship training with site and faculty supervisors. The Integrated Developmental Model (IDM; Stoltenberg, McNeill, & Delworth, 1998) was used to highlight beginning supervisees’ developmental needs and vulnerability to harmful supervision. The significance of the study is two fold. First, I reviewed the previous literature and offered a reconceptualization explaining the outcomes of supervision as influenced by the supervisory relationship, with contributions from both the supervisor and supervisee. Second, the current research identified a detailed description of harmful supervision, as called for by Ellis (2001). Strategies for the prevention and management of harmful supervision for supervisees, supervisors, and counselor educators are provided. Finally, recommendations for future research are outlined
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