Hardening High-Assurance Security Systems with Trusted Computing

We are living in the time of the digital revolution in which the world we know changes beyond recognition every decade. The positive aspect is that these changes also drive the progress in quality and availability of digital assets crucial for our societies. To name a few examples, these are broadly available communication channels allowing quick exchange of knowledge over long distances, systems controlling automatic share and distribution of renewable energy in international power grid networks, easily accessible applications for early disease detection enabling self-examination without burdening the health service, or governmental systems assisting citizens to settle official matters without leaving their homes. Unfortunately, however, digitalization also opens opportunities for malicious actors to threaten our societies if they gain control over these assets after successfully exploiting vulnerabilities in the complex computing systems building them. Protecting these systems, which are called high-assurance security systems, is therefore of utmost importance. For decades, humanity has struggled to find methods to protect high-assurance security systems. The advancements in the computing systems security domain led to the popularization of hardware-assisted security techniques, nowadays available in commodity computers, that opened perspectives for building more sophisticated defense mechanisms at lower costs. However, none of these techniques is a silver bullet. Each one targets particular use cases, suffers from limitations, and is vulnerable to specific attacks. I argue that some of these techniques are synergistic and help overcome limitations and mitigate specific attacks when used together. My reasoning is supported by regulations that legally bind high-assurance security systems' owners to provide strong security guarantees. These requirements can be fulfilled with the help of diverse technologies that have been standardized in the last years. In this thesis, I introduce new techniques for hardening high-assurance security systems that execute in remote execution environments, such as public and hybrid clouds. I implemented these techniques as part of a framework that provides technical assurance that high-assurance security systems execute in a specific data center, on top of a trustworthy operating system, in a virtual machine controlled by a trustworthy hypervisor or in strong isolation from other software. I demonstrated the practicality of my approach by leveraging the framework to harden real-world applications, such as machine learning applications in the eHealth domain. The evaluation shows that the framework is practical. It induces low performance overhead (<6%), supports software updates, requires no changes to the legacy application's source code, and can be tailored to individual trust boundaries with the help of security policies. The framework consists of a decentralized monitoring system that offers better scalability than traditional centralized monitoring systems. Each monitored machine runs a piece of code that verifies that the machine's integrity and geolocation conform to the given security policy. This piece of code, which serves as a trusted anchor on that machine, executes inside the trusted execution environment, i.e., Intel SGX, to protect itself from the untrusted host, and uses trusted computing techniques, such as trusted platform module, secure boot, and integrity measurement architecture, to attest to the load-time and runtime integrity of the surrounding operating system running on a bare metal machine or inside a virtual machine. The trusted anchor implements my novel, formally proven protocol, enabling detection of the TPM cuckoo attack. The framework also implements a key distribution protocol that, depending on the individual security requirements, shares cryptographic keys only with high-assurance security systems executing in the predefined security settings, i.e., inside the trusted execution environments or inside the integrity-enforced operating system. Such an approach is particularly appealing in the context of machine learning systems where some algorithms, like the machine learning model training, require temporal access to large computing power. These algorithms can execute inside a dedicated, trusted data center at higher performance because they are not limited by security features required in the shared execution environment. The evaluation of the framework showed that training of a machine learning model using real-world datasets achieved 0.96x native performance execution on the GPU and a speedup of up to 1560x compared to the state-of-the-art SGX-based system. Finally, I tackled the problem of software updates, which makes the operating system's integrity monitoring unreliable due to false positives, i.e., software updates move the updated system to an unknown (untrusted) state that is reported as an integrity violation. I solved this problem by introducing a proxy to a software repository that sanitizes software packages so that they can be safely installed. The sanitization consists of predicting and certifying the future (after the specific updates are installed) operating system's state. The evaluation of this approach showed that it supports 99.76% of the packages available in Alpine Linux main and community repositories. The framework proposed in this thesis is a step forward in verifying and enforcing that high-assurance security systems execute in an environment compliant with regulations. I anticipate that the framework might be further integrated with industry-standard security information and event management tools as well as other security monitoring mechanisms to provide a comprehensive solution hardening high-assurance security systems

Electronic identification for universities: Building cross-border services based on the eIDAS infrastructure

The European Union (EU) Regulation 910/2014 on electronic IDentification, Authentication, and trust Services (eIDAS) for electronic transactions in the internal market went into effect on 29 September 2018, meaning that EU Member States are required to recognize the electronic identities issued in the countries that have notified their eID schemes. Technically speaking, a unified interoperability platform—named eIDAS infrastructure—has been set up to connect the EU countries’ national eID schemes to allow a person to authenticate in their home EU country when getting access to services provided by an eIDAS-enabled Service Provider (SP) in another EU country. The eIDAS infrastructure allows the transfer of authentication requests and responses back and forth between its nodes, transporting basic attributes about a person, e.g., name, surname, date of birth, and a so-called eIDAS identifier. However, to build new eIDAS-enabled services in specific domains, additional attributes are needed. We describe our approach to retrieve and transport new attributes through the eIDAS infrastructure, and we detail their exploitation in a selected set of academic services. First, we describe the definition and the support for the additional attributes in the eIDAS nodes. We then present a solution for their retrieval from our university. Finally, we detail the design, implementation, and installation of two eIDAS-enabled academic services at our university: the eRegistration in the Erasmus student exchange program and the Login facility with national eIDs on the university portal

Proceedings of the 2nd International Workshop on Security in Mobile Multiagent Systems

This report contains the Proceedings of the Second Workshop on Security on Security of Mobile Multiagent Systems (SEMAS2002). The Workshop was held in Montreal, Canada as a satellite event to the 5th International Conference on Autonomous Agents in 2001. The far reaching influence of the Internet has resulted in an increased interest in agent technologies, which are poised to play a key role in the implementation of successful Internet and WWW-based applications in the future. While there is still considerable hype concerning agent technologies, there is also an increasing awareness of the problems involved. In particular, that these applications will not be successful unless security issues can be adequately handled. Although there is a large body of work on cryptographic techniques that provide basic building-blocks to solve specific security problems, relatively little work has been done in investigating security in the multiagent system context. Related problems are secure communication between agents, implementation of trust models/authentication procedures or even reflections of agents on security mechanisms. The introduction of mobile software agents significantly increases the risks involved in Internet and WWW-based applications. For example, if we allow agents to enter our hosts or private networks, we must offer the agents a platform so that they can execute correctly but at the same time ensure that they will not have deleterious effects on our hosts or any other agents / processes in our network. If we send out mobile agents, we should also be able to provide guarantees about specific aspects of their behaviour, i.e., we are not only interested in whether the agents carry out-out their intended task correctly. They must defend themselves against attacks initiated by other agents, and survive in potentially malicious environments. Agent technologies can also be used to support network security. For example in the context of intrusion detection, intelligent guardian agents may be used to analyse the behaviour of agents on a firewall or intelligent monitoring agents can be used to analyse the behaviour of agents migrating through a network. Part of the inspiration for such multi-agent systems comes from primitive animal behaviour, such as that of guardian ants protecting their hill or from biological immune systems

A study of the security implications involved with the use of executable World Wide Web content

Malicious executable code is nothing new. While many consider that the concept of malicious code began in the 1980s when the first PC viruses began to emerge, the concept does in fact date back even earlier. Throughout the history of malicious code, methods of hostile code delivery have mirrored prevailing patterns of code distribution. In the 1980s, file infecting and boot sector viruses were common, mirroring the fact that during this time, executable code was commonly transferred via floppy disks. Since the 1990s email has been a major vector for malicious code attacks. Again, this mirrors the fact that during this period of time email has been a common means of sharing code and documents. This thesis examines another model of executable code distribution. It considers the security risks involved with the use of executable code embedded or attached to World Wide Web pages. In particular, two technologies are examined. Sun Microsystems\u27 Java Programming Language and Microsoft\u27s ActiveX Control Architecture are both technologies that can be used to connect executable program code to World Wide Web pages. This thesis examines the architectures on which these technologies are based, as well as the security and trust models that they implement. In doing so, this thesis aims to assess the level of risk posed by such technologies and to highlight similar risks that might occur with similar future technologies. ()

Shibboleth and the challenge of authentication in multiple servers on a e-learning environment

L' objectiu d’aquest treball és l’estudi, implementació i prova d'un sistema de autentificació compartida per a múltiples servidors. Encara que des d'un principi es sabia que es treballaria amb Shibboleth també s’han tingut en compte altres possibles solucions. Shibboleth és un projecte desenvolupat per els membres de les universitats que formen el consorci Internet2 amb l’ objectiu de desenvolupar un nou middleware per a realitzar les funcions d’autentificació compartida en múltiples servidors i pensat específicament per facilitar la col·laboració entre institucions i l’accés a continguts digitals. Shibboleth és una solució complerta ja que contempla des de l’autentificació , autorització i accounting, fins al sistema de login i els atributs a emprar. La qual cosa fa que es converteixi en un entorn de treball molt segur però amb l’avantatge d’aportar privacitat als usuaris. El primer objectiu ha estat identificar les peculiaritats i requeriments dels entorns de elearning distribuïts, per això s’ha estudiat conceptes específics de seguretat així com la manera d’adaptar-los a l’entorn requerit. Desprès s’ha fet una comparativa de les solucions existents al mercat amb una funcionalitat similar a Shibboleth, per tal de presentar els avantatges i desavantatges de Shibboleth vers aquests. Posteriorment, el treball ha consistit en entendre la estructura i els principis de funcionament de Shibboleth, quin tipus de requeriments tenia, el funcionament i objectius de cada part, estudiar els requeriments de l’entorn específic per al qual ha estat dissenyat (e-learning) i donar una idea general de com s’ hauria de fer la implementació. També s’han estudiat totes les tecnologies i requeriments necessaris per desenvolupar Shibboleth. Una vegada estudiat Shibboleth i l'entorn específic en el que s’hauria d’integrar, s’ha muntat un escenari per a la posada en marxa i proves d’aquest, provant específicament cada part i entenent amb les proves reals el funcionament. Amb l’escenari en funcionament, la idea era integrar Shibboleth amb Sakai i Blackboard, els CMS (Course Management System) utilitzats a on-campus, el campus virtual de la Fachhochschule Lübeck. Per a finalitzar i a mode de conclusions s'ha fet una petita explicació dels resultats obtinguts, una valoració de com Shibboleth resoldria les necessitats plantejades i algunes propostes de millora

Multi-agent system security for mobile communication

This thesis investigates security in multi-agent systems for mobile communication. Mobile as well as non-mobile agent technology is addressed. A general security analysis based on properties of agents and multi-agent systems is presented along with an overview of security measures applicable to multi-agent systems, and in particular to mobile agent systems. A security architecture, designed for deployment of agent technology in a mobile communication environment, is presented. The security architecture allows modelling of interactions at all levels within a mobile communication system. This architecture is used as the basis for describing security services and mechanisms for a multi-agent system. It is shown how security mechanisms can be used in an agent system, with emphasis on secure agent communication. Mobile agents are vulnerable to attacks from the hosts on which they are executing. Two methods for dealing with threats posed by malicious hosts to a trading agent are presented. The rst approach uses a threshold scheme and multiple mobile agents to minimise the eect of malicious hosts. The second introduces trusted nodes into the infrastructure. Undetachable signatures have been proposed as a way to limit the damage a malicious host can do by misusing a signature key carried by a mobile agent. This thesis proposes an alternative scheme based on conventional signatures and public key certicates. Threshold signatures can be used in a mobile agent scenario to spread the risk between several agents and thereby overcome the threats posed by individual malicious hosts. An alternative to threshold signatures, based on conventional signatures, achieving comparable security guarantees with potential practical advantages compared to a threshold scheme is proposed in this thesis. Undetachable signatures and threshold signatures are both concepts applicable to mobile agents. This thesis proposes a technique combining the two schemes to achieve undetachable threshold signatures. This thesis denes the concept of certicate translation, which allows an agent to have one certicate translated into another format if so required, and thereby save storage space as well as being able to cope with a certicate format not foreseen at the time the agent was created

Design principles and patterns for computer systems that are simultaneously secure and usable

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2005.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Includes bibliographical references (p. 429-464) and index.It is widely believed that security and usability are two antagonistic goals in system design. This thesis argues that there are many instances in which security and usability can be synergistically improved by revising the way that specific functionality is implemented in many of today's operating systems and applications. Specific design principles and patterns are presented that can accomplish this goal. Patterns are presented that minimize the release of confidential information through remnant and remanent data left on hard drives, in web browsers, and in documents. These patterns are based on a study involving the purchase of 236 hard drives on the secondary market, interviews conducted with organizations whose drives had been acquired, and through a detailed examination of modern web browsers and reports of information leakage in documents. Patterns are presented that enable secure messaging through the adoption of new key management techniques. These patterns are supported through an analysis of S/MIME handling in modern email clients, a survey of 469 Amazon.com merchants, and a user study of 43 individuals. Patterns are presented for promoting secure operation and for reducing the danger of covert monitoring. These patterns are supported by the literature review and an analysis of current systems.(cont.) In every case considered, it is shown that the perceived antagonism of security and usability can be scaled back or eliminated by revising the underlying designs on which modern systems are conceived. In many cases these designs can be implemented without significant user interface changes. The patterns described in this thesis can be directly applied by today's software developers and used for educating the next generation of programmers so that longstanding usability problems in computer security can at last be addressed. It is very likely that additional patterns can be identified in other related areas.by Simson L. Garfinkel.Ph.D

SoK: A Systematic Review of TEE Usage for Developing Trusted Applications

Trusted Execution Environments (TEEs) are a feature of modern central processing units (CPUs) that aim to provide a high assurance, isolated environment in which to run workloads that demand both confidentiality and integrity. Hardware and software components in the CPU isolate workloads, commonly referred to as Trusted Applications (TAs), from the main operating system (OS). This article aims to analyse the TEE ecosystem, determine its usability, and suggest improvements where necessary to make adoption easier. To better understand TEE usage, we gathered academic and practical examples from a total of 223 references. We summarise the literature and provide a publication timeline, along with insights into the evolution of TEE research and deployment. We categorise TAs into major groups and analyse the tools available to developers. Lastly, we evaluate trusted container projects, test performance, and identify the requirements for migrating applications inside them.Comment: In The 18th International Conference on Availability, Reliability and Security (ARES 2023), August 29 -- September 01, 2023, Benevento, Italy. 15 page

Blockchain in Education

This report introduces the fundamental principles of the Blockchain focusing on its potential for the education sector. It explains how this technology may both disrupt institutional norms and empower learners. It proposes eight scenarios for the application of the Blockchain in an education context, based on the current state of technology development and deployment.JRC.B.4-Human Capital and Employmen

A generic framework for process execution and secure multi-party transaction authorization

Process execution engines are not only an integral part of workflow and business process management systems but are increasingly used to build process-driven applications. In other words, they are potentially used in all kinds of software across all application domains. However, contemporary process engines and workflow systems are unsuitable for use in such diverse application scenarios for several reasons. The main shortcomings can be observed in the areas of interoperability, versatility, and programmability. Therefore, this thesis makes a step away from domain specific, monolithic workflow engines towards generic and versatile process runtime frameworks, which enable integration of process technology into all kinds of software. To achieve this, the idea and corresponding architecture of a generic and embeddable process virtual machine (ePVM), which supports defining process flows along the theoretical foundation of communicating extended finite state machines, are presented. The architecture focuses on the core process functionality such as control flow and state management, monitoring, persistence, and communication, while using JavaScript as a process definition language. This approach leads to a very generic yet easily programmable process framework. A fully functional prototype implementation of the proposed framework is provided along with multiple example applications. Despite the fact that business processes are increasingly automated and controlled by information systems, humans are still involved, directly or indirectly, in many of them. Thus, for process flows involving sensitive transactions, a highly secure authorization scheme supporting asynchronous multi-party transaction authorization must be available within process management systems. Therefore, along with the ePVM framework, this thesis presents a novel approach for secure remote multi-party transaction authentication - the zone trusted information channel (ZTIC). The ZTIC approach uniquely combines multiple desirable properties such as the highest level of security, ease-of-use, mobility, remote administration, and smooth integration with existing infrastructures into one device and method. Extensively evaluating both, the ePVM framework and the ZTIC, this thesis shows that ePVM in combination with the ZTIC approach represents a unique and very powerful framework for building workflow systems and process-driven applications including support for secure multi-party transaction authorization