The ease of copying digital materials creates difficulty in detecting the theft of digital certificates. Uneducated users frequently fail to protect their digital certificate keys by not encrypting them, storing them in insecure places, and using them unwisely. In addition, there is no way to prove that protocols involving certificates are completely secure. This thesis introduces a system to ameliorate these problems by detecting the compromise of digital certificates. It leverages dual logging messages sent via side channels to a trusted third party. This third party correlates these messages and automatically detects when an imposter presents a certificate based on the collected evidence.

The aim of this master thesis is to convey an ellaborate overview of Secure Boot, the technology used for an authentization during a platfrom boot up. Overview is followed by a description of contemporary implementations of Secure Boot found in the operating systems based on the Linux kernel. Finally, we propose a new implemenation of Secure Boot support in the systemd-boot project.

O surgimento e a popularização de arquiteturas de software que fornecem suporte à programação distribuída orientada a objetos, como CORBA, .NET e Java EE, gerou uma demanda por infra-estruturas de segurança eficientes, capazes de proteger os recursos dos sistemas de ataques maliciosos. Essa proteção começa pela identificação dos usuários que interagem com os sistemas, processo conhecido como autenticação. Entretanto, a autenticação por si só não é suficiente para garantir a segurança dos recursos, uma vez que a autenticação não determina quais ações os usuários estão autorizados a executar depois de autenticados. Em outras palavras, um mecanismo de autorização, que faz valer as políticas de controle de acesso aos recursos definidas pelos administradores de sistemas, se faz necessário. Neste trabalho estudamos mecanismos de controle de acesso baseado em papéis e a aplicabilidade dos certificados de atributos X.509 como estrutura de armazenamento desses papéis em um ambiente Java EE. Em particular, estendemos a infra-estrutura de segurança do servidor de aplicações JBoss, de modo que ela passasse a comportar os certificados de atributos X.509. Além disso, analisamos as vantagens e desvantagens do uso de tais certificados e avaliamos o desempenho da extensão desenvolvida em relação a outras alternativas que são oferecidas pelo JBoss para o armazenamento de papéis dos usuários. / The popularization of software architectures that provide support for distributed object-oriented programming, like CORBA, .NET, and Java EE, revealed the need for efficient security infrastructures to protect the resources of enterprise systems from malicious attacks. This protection usually begins with the identification of the users that interact with the systems, a process known as authentication. However, authentication alone is not enough to guarantee the protection of the resources, as it cannot determine what actions a particular user is allowed to execute on a given resource. In other words, an authorization mechanism is needed in order to enforce the access control policies as defined by the system administrators. In this dissertation we studied role-based access control mechanisms and the use of X.509 attribute certificates as data structures that store the users roles in a Java EE environment. Particularly, we added X.509 attribute certificates support to the existing JBoss application server security infrastructure. Furthermore, we evaluated the pros and cons of using these certificates, and compared the performance of the developed extension to the performance of the existing solutions provided by JBoss to store the users roles.

O surgimento e a popularização de arquiteturas de software que fornecem suporte à programação distribuída orientada a objetos, como CORBA, .NET e Java EE, gerou uma demanda por infra-estruturas de segurança eficientes, capazes de proteger os recursos dos sistemas de ataques maliciosos. Essa proteção começa pela identificação dos usuários que interagem com os sistemas, processo conhecido como autenticação. Entretanto, a autenticação por si só não é suficiente para garantir a segurança dos recursos, uma vez que a autenticação não determina quais ações os usuários estão autorizados a executar depois de autenticados. Em outras palavras, um mecanismo de autorização, que faz valer as políticas de controle de acesso aos recursos definidas pelos administradores de sistemas, se faz necessário. Neste trabalho estudamos mecanismos de controle de acesso baseado em papéis e a aplicabilidade dos certificados de atributos X.509 como estrutura de armazenamento desses papéis em um ambiente Java EE. Em particular, estendemos a infra-estrutura de segurança do servidor de aplicações JBoss, de modo que ela passasse a comportar os certificados de atributos X.509. Além disso, analisamos as vantagens e desvantagens do uso de tais certificados e avaliamos o desempenho da extensão desenvolvida em relação a outras alternativas que são oferecidas pelo JBoss para o armazenamento de papéis dos usuários. / The popularization of software architectures that provide support for distributed object-oriented programming, like CORBA, .NET, and Java EE, revealed the need for efficient security infrastructures to protect the resources of enterprise systems from malicious attacks. This protection usually begins with the identification of the users that interact with the systems, a process known as authentication. However, authentication alone is not enough to guarantee the protection of the resources, as it cannot determine what actions a particular user is allowed to execute on a given resource. In other words, an authorization mechanism is needed in order to enforce the access control policies as defined by the system administrators. In this dissertation we studied role-based access control mechanisms and the use of X.509 attribute certificates as data structures that store the users roles in a Java EE environment. Particularly, we added X.509 attribute certificates support to the existing JBoss application server security infrastructure. Furthermore, we evaluated the pros and cons of using these certificates, and compared the performance of the developed extension to the performance of the existing solutions provided by JBoss to store the users roles.

The problem of SSL/TLS interception ("trusted proxy in SSL/TLS connection") has been known for years and many implementations exist. However, all of them share a single technical solution which is based solely on the PKI authentication mechanism and suffers from multiple serious disadvantages. Most importantly, it is not compatible with several aspects or future trends of SSL/TLS and PKI, there's almost no space for improvement and its real use may spawn legal issues. After we analyze technical background and the current solution, we will propose another one, based not only on PKI but SSL/TLS too. Both solutions will be compared and general superiority of the new one will be shown. Basic implementation and analysis will follow, along with deployment requirements and ideas for future development. Powered by TCPDF (www.tcpdf.org)

This diploma thesis deals with a detection and analysis of secure connections of electro- nic communication through SSL/TLS protocols. The thesis begins with introduction to SSL/TLS protocols. Thereafter, an analysis of messages used to establish secure con- nections using STARTTLS and postal protocols SMTP, POP3, and IMAP was made. Metadata detection and extraction of secured simplex and duplex connections take place using deep packet inspection tools. The tool of choice is the nDPI library from the Ntop project. The library was extended to detect the connections and extract the metadata based on studies and analysis of transmitted messages. Finally, testing is performed on a training data set and a basic analysis of acquired metadata is made.

Today both government agencies and companies struggle to keep up with the pace of the continuous change of technology. With all new technology there are benefits, but new problems might also occur. Implementing new technology for certain tasks may increase both efficiency and security, resulting in a more sustainable work environment. One technology that is increasingly adopted is digital signatures. Instead of using classical handwritten signatures on documents, a digital signature can be more time efficient and have higher security. In order to implement a digital signature technology some security aspects must be addressed and certain properties ensured. In the document signature process, each time an individual verifies a signature attached onto a document a log entry is created. This log contains information about who verified which document, does it have multiple parts that have been signed, does it need multiple signatures in order to be valid, and at what time and date was the document signed. Logs help to ensure the validity of the document and thereby increase the security provided by the digital signatures. At KTH, a student must sign an application form with a regular ink-written signature to start a thesis project. This process can in most cases delay the start up to two weeks. This study aims to implement digital signatures for one specific form, an application form for a thesis project. The hypothesis at the start of the project was that the use of digital signature would decrease the time of waiting significantly. Personnel at KTH using digital signature would facilitate their work efficiency, due to less printing and archiving of papers as well fewer meetings. This study will provide the reader with the necessary fundamental knowledge of cryptography and how digital signatures use this underlying technology. The methodology used in this study was to identify and modify certain software settings, as well collect data from students and personnel at KTH. The collected data was based on time measurements of digital signature processes from students and a faculty member. The results show digital signatures are faster than the current signing process with traditional ink-written signatures. Additionally, the use of digital signatures is expected to reduce the need for printing, transport, and sorting of paper documents. The resulting reduction in use of physical paper should provide environmental benefits. / Dagens myndigheter och företag har det svårt att ständigt följa den tekniska utvecklingen. Ny teknik skapar oftast nya fördelar och andra förmåner men kan ibland också orsaka problem. Att implementera ny teknik för specifika ändamål kan öka både effektivitet och säkerhet, vilket resulterar i en mer effektiv arbetsplats. En teknik som introduceras allt mer på sistone är digitala signaturer. Istället för att signera dokument med en handskriven signatur kan en digital signatur vara mer tidseffektiv och ha en högre säkerhet. För att implementera tekniken bakom digitala signaturer måste särskilda säkerhetsaspekter adresseras och specifika inställningar säkerställas. I signaturprocessen måste varje individ verifiera signaturen som är bifogad på dokumentet, denna verifiering skapar även en logg. En logg innehåller bland annat information om vem som verifierade dokumentet, om dokumentet har fler än en bifogad signatur, behöver dokumentet fler signaturer för att vara giltigt och vilken tid och datum var dokumentet signerat. En logg säkerställer validiteten av dokumentet och ökar därmed säkerheten för digitala signaturer. På KTH krävs en skriftlig ansökan för att påbörja ett examensarbete. Med nuvarande process kan det i vissa fall leda till en försenad projektstart med upp till två veckor. Den här studien syftar till att implementera digitala signaturer för ett specifikt formulär, en ansökningsblankett för att påbörja ett examensarbete. Hypotesen vid projektstart var att användning av digitala signaturer skulle kunna förminska väntetiden signifikant. Anställda på KTH som utnyttjar digitala signaturer skulle kunna förbättra deras arbetseffektivitet på grund av färre pappersutskrifter, mindre pappersarkivering och färre möten. Den här studien kommer att förse läsaren med de mest nödvändiga kunskaperna av kryptografi och hur digitala signaturer använder krypteringsfenomenet. Metodiken som användes syftade till att identifiera och modifiera specifika mjukvaruinställningar samt samla in data från studenter och personal på KTH. Den insamlade datan baserades på tidsmätningar av digitala signatursprocesser från studenter, studievägledare och handledare. Resultatet från studien visade att digitala signaturer skulle ge en snabbare signeringsprocess än nuvarande formulär. Det kan dessutom förväntas att med digitala signaturer skulle pappersutskrifter, papperstransporter och sortering av dessa dokument reduceras. Resultatet av minskad användning av fysiskt papper kommer att generera arbetsfördelar.

The migration of signing algorithms is a process which can be used to move from signing algorithms which are regarded as less safe to algorithms which are regarded as safer. The safety of cryptographic algorithms has been compromised before, algorithms such as SHA-1 has been proven to be broken. The goal of this study was to find criteria that could define a successful migration as well as evaluating a method to perform a migration. The criteria were found by evaluating related works found in an RFC document as well as in a Springer conference paper. The criteria that was found was the following: backwards compatibility, no downtime, no need for mass revocation, no need for strict scheduling and no extra overhead. The evaluated method utilized a construct called a multiple key certificate; it was chosen because it conformed to most of the found criteria. The multiple key certificate utilized two different key pairs, one generated from a conventional algorithm and the other using an alternative algorithm, it also conformed to the x.509 standard. The alternative algorithm could be chosen to be a post quantum algorithm. The prototype was tested for time overhead, memory overhead and backward compatibility. The results of testing to sign and verify 10 000 certificates as well as examining the file size of the certificate showed that the choice of alternative algorithm heavily affects the time overhead of the prototype certificate. The multiple key certificate also proved to be backwards compatible with widely used applications. This solution has proven itself to act in accordance to all the newly established criterion except for the criterion regarding overhead however, alternative algorithms could be strategically chosen to minimize overhead. The multiple key certificate seems to be a successful way to migrate signing algorithms. / Migration av signeringsalgoritmer som används i certifikat är en process som kan behövas när en signeringsalgoritm som är mindre säker ska ersättas med en som är mer säker. Säkerheten som återfinns hos kryptografiska algoritmer har brutits förut, algoritmer såsom SHA-1 har bevisats vara osäkra. Målet med denna studie var att ta fram kriterier som kan definiera en lyckad migration samt evaluera en metod som kan användas för att utföra en migration. Kriterierna togs fram genom att studera tidigare arbeten inom migration av signeringsalgoritmer, dessa arbeten återfinns hos RFC dokument samt konferensrapporter från Springer. Kriterierna som togs fram var följande: kompatibilitet med äldre system, ingen nertid, inget behov av massrevokering, inget behov av strikta tidsscheman samt ingen extra omkostnad. Metoden som utvärderades kallas för flernyckels certifikat. Den valdes för att den följde flest av de nyfunna kriterierna. Lösningen utnyttjar två olika nyckelpar, nämligen ett nyckelpar som har genererats med en konventionell algoritm samt ett nyckelpar som har genererats med en alternativ algoritm. Lösningen följer även x.509 standarden. Den alternativa algoritmen kan väljas så att den är postkvantum. Prototypen testades för omkostnad i tid samt minne genom att signera och verifiera 10 000 certifikat samt att titta på certifikatens filstorlek. Prototypen testades även för kompatibilitet med kända applikationer. Resultaten visade att valet av alternativa algoritmer hade stor påverkan på omkostnaderna. Tester visade att prototypen var kompatibel med applikationer som används i stor utsträckning. Lösningen verkade följa alla nyfunna kriterier förutom kriteriet angående omkostnad men den alternativa algoritmen kan strategiskt väljas för att minimera omkostnaden. Prototypen verkar vara ett lyckat sätt att migrera signeringsalgoritmer.

X.509 certificate revocation defends against man-in-the-middle attacks involving a compromised certificate. Certificate revocation strategies face scalability, effectiveness, and deployment challenges as HTTPS adoption rates have soared. We propose Certificate Revocation Table (CRT), a new revocation strategy that is competitive with or exceeds alternative state-of-the-art solutions in effectiveness, efficiency, certificate growth scalability, mass revocation event scalability, revocation timeliness, privacy, and deployment requirements. The CRT periodically checks the revocation status of X.509 certificates recently used by an organization, such as clients on a university's private network. By prechecking the revocation status of each certificate the client is likely to use, the client can avoid the security problems of on-demand certificate revocation checking. To validate both the effectiveness and efficiency of using a CRT, we used 60 days of TLS traffic logs from Brigham Young University to measure the effects of actively refreshing certificates for various certificate working set window lengths. Using a certificate working set window size of 45 days, an average of 99.86% of the TLS handshakes from BYU would have revocation information cached in advance using our approach. Revocation status information can be initially downloaded by clients with a 6.7 MB file and then subsequently updated using only 205.1 KB of bandwidth daily. Updates to this CRT that only include revoked certificates require just 215 bytes of bandwidth per day.

Este trabajo presenta tanto el estado del arte como un análisis de los principales sistemas de revocación de certificados digitales. El hecho de comprender bien el mecanismo de revocación de un certificado es importante tanto para los proveedores de servicios PKI como para los usuarios finales de la PKI: una mejor comprensión de las complejidades del sistema de revocación permite a estas entidades mejorar su proceso de decisión a la hora de aceptar o rechazar un certificado teniendo en cuenta la gran cantidad de variables inherentes en los sistemas de revocación. La revocación de certificados se presenta como uno de los problemas más complejos a resolver en toda la PKI. Por tanto este aspecto se está convirtiendo en un punto crucial para el amplio desarrollo de las PKIs. Hay estudios que incluso argumentan que los costes de la PKI derivan en gran medida de la administración de la revocación.Esto nos ha motivado para desarrollar nuevas propuestas. En este sentido, hemos desarrollado tres propuestas: H-OCSP (propuesta de mejora basada en el estándar OCSP), AD-MHT (propuesta basada en los árboles de hash de Merkle) y E-MHT (propuesta que aglutina varios mecanismos que permiten mejorar la eficiencia de los sistemas tradicionales basados en el árbol de hash de Merkle). Las propuestas que se plantean en esta tesis no son solo un conjunto de mecanismos teóricos sino que son también sistemas prácticos que han sido implementados como parte de una plataforma de pruebas llamada Cervantes. El diseño de Cervantes permite además encajar cualquier otro tipo de sistema de revocación sin cambios significativos en la estructura o el código fuente de la plataforma. En particular, en esta tesis se detalla como se han implementado los dos grandes estándares de revocación: CRL y OCSP y como se han implementado las propuestas realizadas. Finalmente utilizando Cervantes se pueden observar resultados de rendimiento para todos los sistemas estudiados y en particular nuestras propuestas han demostrado finalmente ser más escalables y eficientes en tratamiento de la información de revocación que las propuestas anteriores. / Certificates are necessary but not sufficient to secure transactions between parties. The Public Key Infrastructure (PKI) has to provide its users the ability to check, at the time of usage, that certificates are still valid (not revoked). So understanding revocation is an important concern to both PKI service providers and end users. By a better understanding of the complexities of certificate revocation, certificate-using entities can improve their decision-making process in order to accept or reject a certain certificate. In this sense, this thesis presents a comprehensive survey and analysis of the main existing revocation schemes. Furthermore, the certificate revocation represents one of the hardest scalability problems of the whole PKI; so this aspect is getting more and more crucial with the development of wide spread PKIs. There are studies that even argue that the running expenses of a PKI derives mainly from administering revocation. This motivate us to propose scalable, timely, secure, and cost-effective systems to manage the revocation information. In this respect, we have three new proposals: H-OCSP (which is a modification over the standard OCSP), AD-MHT (which is based on the Merkle Hash Tree) and E-MHT (which agglutinates several mechanisms that enhance the efficiency of traditional MHT-based systems). Our proposals are not only a set of theoretical mechanisms but they are also practical systems that have been implemented inside a Java test-bed called Cervantes (Certificate Validation Test-bed). The design of Cervantes allows it to fit any kind of revocation system without significative changes in the structure or the source code of the platform. Finally using Cervantes we are able to obtain performance results about each system developed.