With the constant evolution of hardware architecture extensions aimed at enhancing software security, a notable availability gap arises due to the proprietary nature and design-specific characteristics of these features, resulting in a CPU-specific implementation. This gap particularly affects low-end embedded devices that often rely on CPU cores with limited resources. Addressing this challenge, this thesis focuses on providing access to hardware-based Trusted Execution Environments (TEEs) for devices lacking TEE support. RSGX is a framework crafted to transparently offload security-sensitive workloads to an enclave hosted in a remote centralized edge server. Operating as clients, low-end TEE-lacking devices can harness the hardware security features provided by TEEs of either the same or different architecture. RSGX is tailored to accommodate applications developed with diverse TEE-utilizing SDKs, such as the Open Enclave SDK, Intel SGX SDK, and many others. This facilitates easy integration of existing enclave-based applications, and the framework allows users to utilize its features without requiring any source code modifications, ensuring transparent offloading behind the scenes. For the evaluation, we set up an edge computing environment to execute C/C++ applications, including two overhead micro-benchmarks and four popular open-source applications. This evaluation of RSGX encompasses an analysis of its security benefits and a measurement of its performance overhead. We demonstrate that RSGX has the potential to mitigate a range of Common Vulnerability Exposures (CVEs), ensuring the secure execution of confidential computations on hybrid and distributed machines with an acceptable performance overhead. / Master of Science / A vast amount of data is generated globally every day, most of which contains critical information and is often linked to individuals. Therefore, safeguarding data is essential at every stage, whether it's during transmission, storage, or processing. Different security principles are applied to protect data at various stages. This thesis particularly focuses on data in use. To protect data in use, several technologies are available, and one of them is confidential computing, which is a hardware-based security technology. However, confidential computing is limited to certain high-end computing machines, and many resource-constrained devices do not support it. In this thesis, we propose RSGX, a framework to offload secured computation to a confidential computing-capable remote device with a Security as a Service (SECaaS) approach. Through RSGX, users can leverage confidential computing capabilities for any of their applications based on any SDK. RSGX provides this capability transparently and securely. Our evaluation shows that users, by adapting RSGX, can mitigate several security vulnerabilities, thereby enhancing security with a reasonable overhead.

Hardware-Assisted Trusted Execution Environment technologies have become a crucial component in providing security for cloud-based computing. One of such hardware-assisted countermeasures is Intel Software Guard Extension (SGX). Using additional dedicated hardware and a new set of CPU instructions, SGX is able to provide isolated execution of code within trusted hardware containers called enclaves. By utilizing private encrypted memory and various integrity authentication mechanisms, it can provide confidentiality and integrity guarantees to protected data. In spite of dedicated hardware, these extra layers of security add a significant performance overhead. Decryption of data using secret OTPs, which are generated by modified Counter Mode Encryption AES blocks, results in a significant latency overhead that contributes to the overall SGX performance loss. This thesis introduces a metadata prediction extension to SGX based on local metadata releveling and prediction mechanisms. Correct prediction of metadata allows to speculatively precompute OTPs, which can be immediately used in decryption of incoming ciphertext data. This hides a significant part of decryption latency and results in faster SGX performance without any changes to the original SGX security guarantees. / Master of Science / With the exponential growth of cloud computing, where critical data processing is happening on third-party computer systems, it is important to ensure data confidentiality and integrity against third-party access. Sometimes that may include not only external attackers, but also insiders, like cloud computing providers themselves. While software isolation using Virtual Machines is the most common method of achieving runtime security in cloud computing, numerous shortcomings of software-only countermeasures force companies to demand extra layers of security. Recently adopted general purpose hardware-assisted technology like Intel Software Guard Extension (SGX) add that extra layer of security at the significant performance overhead. One of the major contributors to the SGX performance overhead is data decryption latency. This work proposes a novel algorithm to speculatively predict metadata that is used during decryption. This allows the processor to hide a significant portion of decryption latency, thus improving the overall performance of Intel SGX without compromising security.

Submitted by Emanuel Varela Cardoso (emanuel.varela@ufcg.edu.br) on 2018-09-06T19:50:33Z No. of bitstreams: 1 LÍLIA RODRIGUES SAMPAIO – DISSERTAÇÃO (PPGCC) 2018.pdf: 2337190 bytes, checksum: bfef42889bed89a3860b61f38016b02d (MD5) / Made available in DSpace on 2018-09-06T19:50:33Z (GMT). No. of bitstreams: 1 LÍLIA RODRIGUES SAMPAIO – DISSERTAÇÃO (PPGCC) 2018.pdf: 2337190 bytes, checksum: bfef42889bed89a3860b61f38016b02d (MD5) Previous issue date: 2018-02-15 / Capes / O alto poder computacional oferecido por provedores de nuvem, aliado às suas características de flexibilidade, eficiência e custo reduzido, têm levado cada vez mais usuários a utilizar recursos em nuvem para implantação de aplicações. Como consequência, uma grande quantidade de dados de diversas aplicações críticas, e de alta demanda de processamento, passam a trafegar livremente pela nuvem. Considerando isso, especialmente para aplicações que lidam com dados sensíveis, como sistemas bancários, medidores inteligentes de energia, entre outros, é de grande importância assegurar a integridade e confidencialidade de tais dados. Assim, é cada vez mais frequente que usuários de recursos de uma nuvem exijam garantias de que suas aplicações estão executando em um ambiente de execução confiável. Abordagens tradicionais, como criptografia de dados em repouso e em comunicação, combinadas com políticas rígidas de controle de acesso têm sido usadas com algum êxito, mas ainda têm permitido sérios ataques. No entanto, mais recentemente,Trusted Execution Environments(TEE) têm prometido garantias de integridade e confidencialidade de dados e códigos ao carregá-los e executálos em áreas seguras e isoladas do processador da máquina. Assim, para dar suporte a implementações de TEE, tecnologias de segurança em hardware podem ser utilizadas, como ARM Trustzone e Intel SGX. No contexto deste trabalho, usamos Intel SGX, que se propõe a garantir confidencialidade e integridade de dados e aplicações executadas dentro de áreas protegidas de memória, denominadas enclaves. Assim, o código é protegido até de software com acesso privilegiado, como o próprio sistema operacional, hipervisores, entre outros. Diversos recursos da nuvem podem fazer uso de tais tecnologias de segurança, entre eles máquinas virtuais e contêineres. Neste estudo, propomos estratégias para o suporte de TEE em ambientes de nuvem, integrando Intel SGX e OpenStack, uma plataforma de nuvem de código berto amplamente conhecida e utilizada por grandes empresas. Apresentamos uma nova bordagem no processo de provisionamento e escalonamento de máquinas virtuais e contêineres numa nuvem OpenStack segura, que considera aspectos essenciais para o SGX, como a quantidade de memória segura sendo utilizada, oEnclave Page Cache(EPC). Porfim, validamos esta nuvem com uma aplicação que exige processamento de dados sensíveis. / The high level of computing power offered by cloud providers, together with theflexibility, efficiency and reduced cost they also offer, have increased the number of users wanting to deploy their applications on the cloud. As a consequence, a big amount of data from many critical and high performance applications start to traffic on the cloud. Considering this, specially for applications that deal with sensitive data, such as bank transactions, smart metering, and others, is very important to assure data integrity and confidentiality. Thus, it is increasingly common that users of cloud resources demand guarantees that their applications are running on trusted execution environments. Traditional approaches, such as data cryptography, combined with strict access control policies have been used with a level of success, but still allowing serious attacks. However, more recently, Trusted Execution Environments (TEE) are promising guarantees of data and code integrity and confidentiality by loading and executing them in isolated secure areas of the machine’s processor. This way, to support TEE implementations, hardware technologies such as ARM TrustZone and Intel SGX can be used. In the context of this research, we use Intel SGX, which proposes integrity and confidentiality guarantees for data and applications executed inside protected memory areas called enclaves. Thus, the code is protected even from high privileged software, such as the operational system, hypervisors and others. Many cloud resources can use such security technologies, like virtual machines and containers. In this research, we propose strategies to support TEE in cloud environments, integrating Intel SGX and OpenStack, an open-source cloud platform widely known and used by many big companies. We present a new approach in the provisioning and scheduling of instances in a secure OpenStack cloud, considering essential aspects to SGX such as the amount of secure memory being used, the Enclave Page Cache (EPC). Finally, we validated this cloud by deploying an application that requires processing of sensitive data.

The advent of virtualization introduced the need for virtual switches to interconnect virtual machines deployed in a cloud infrastructure. With Software Defined Networking (SDN), a central controller can configure these virtual switches. Virtual switches execute on commodity operating systems. Open vSwitch is an open source project that is widely used in production cloud environments. If an adversary gains access with full privileges to the operating system hosting the virtual switch, then Open vSwitch becomes vulnerable to a variety of different attacks that could compromise the whole network. The purpose of this thesis project is to improve the security of Open vSwitch implementations in order to ensure that only authenticated switches and controllers can communicate with each other, while maintaining code integrity and confidentiality of keys and certificates. The thesis project proposes a design and shows an implementation that leverages Intel® Safe Guard Extensions (SGX) technology. A new library, TLSonSGX, is implemented. This library replaces the use of the OpenSSL library in Open vSwitch. In addition to implementing standard Transport Level Security (TLS) connectivity, TLSonSGX confines TLS communication in the protected memory enclave and hence protects TLS sensitive components necessary to provide confidentiality and integrity, such as private keys and negotiated symmetric keys. Moreover, TLSonSGX introduces new, secure, and automatic means to generate keys and obtain signed certificates from a central Certificate Authority that validates using Linux Integrity Measurements Architecture (IMA) that the Open vSwitch binaries have not been tampered with before issuing a signed certificate. The generated keys and obtained certificates are stored in the memory enclave and hence never exposed as plaintext outside the enclave. This new mechanism is a replacement for the existing manual and unsecure procedures (as described in Open vSwitch project). A security analysis of the system is provided as well as an examination of performance impact of the use of a trusted execution environment. Results show that generating keys and certificates using TLSonSGX takes less than 0.5 seconds while adding 30% latency overhead for the first packet in a flow compared to using OpenSSL when both are executed on Intel® CoreTM i7-6600U processor clocked at 2.6 GHz. These results show that TLSonSGX can enhance Open vSwitch security and reduce its TLS configuration overhead. / Framkomsten av virtualisering införde behovet av virtuella växlar för att koppla tillsammans virtuella maskiner placerade i molninfrastruktur. Med mjukvarubaserad nätverksteknik (SDN), kan ett centralt styrenhet konfigurera dessa virtuella växlar. Virtuella växlar kör på standardoperativsystem. Open vSwitch är ett open-source projekt som ofta används i molntjänster. Om en motståndare får tillgång med fullständiga privilegier till operativsystemet där Open vSwitch körs, blir Open vSwitch utsatt för olika attacker som kan kompromettera hela nätverket.  Syftet med detta examensarbete är att förbättra säkerheten hos Open vSwitch för att garantera att endast autentiserade växlar och styrenheter kan kommunicera med varandra, samtidigt som att upprätthålla kod integritet och konfidentialitet av nycklar och certifikat. Detta examensarbete föreslår en design och visar en implementation som andvändar Intel®s Safe Guard Extensions (SGX) teknologi. Ett nytt bibliotek, TLSonSGX, är implementerat. Detta bibliotek ersätter biblioteket OpenSSL i Open vSwitch. Utöver att det implementerar ett standard “Transport Layer Security” (TLS) anslutning, TLSonSGX begränsar TLS kommunikation i den skyddade minnes enklaven och skyddar därför TLS känsliga komponenter som är nödvändiga för att ge sekretess och integritet, såsom privata nycklar och förhandlade symmetriska nycklar. Dessutom introducerar TLSonSGX nya, säkra och automatiska medel för att generera nycklar och få signerade certifikat från en central certifikatmyndighet som validerar, med hjälp av Linux Integrity Measurements Architecture (IMA), att Open vSwitch-binärerna inte har manipulerats innan de utfärdade ett signerat certifikat. De genererade nycklarna och erhållna certifikat lagras i minnes enklaven och är därför aldrig utsatta utanför enklaven. Denna nya mekanism ersätter de manuella och osäkra procedurerna som beskrivs i Open vSwitch projektet. En säkerhetsanalys av systemet ges såväl som en granskning av prestandaffekten av användningen av en pålitlig exekveringsmiljö. Resultaten visar att använda TLSonSGX för att generera nycklar och certifikat tar mindre än 0,5 sekunder medan det lägger 30% latens overhead för det första paketet i ett flöde jämfört med att använda OpenSSL när båda exekveras på Intel® Core TM processor i7-6600U klockad vid 2,6 GHz. Dessa resultat visar att TLSonSGX kan förbättra Open vSwitch säkerhet och minska TLS konfigurationskostnaden.

In recent years, the desire for financial privacy and anonymity spurred the growth of electronic cash and cryptocurrencies. The introduction of decentralized cryptocurrencies, such as Bitcoin, accelerated their adoption in society. Since digital information is easier to reproduce, digital currencies are vulnerable to be spent more than once – this is called a double-spending attack. In order to prevent double-spending, Bitcoin records transactions in a tamper-resilient shared ledger called the blockchain. However, the time required to generate new blocks in the blockchain causes a delay in the transaction confirmation. This delay, typically around one hour in Bitcoin, is impractical for real world trade and limits the wide-spread use of blockchain-based cryptocurrencies. In this thesis, we propose a solution to prevent double-spending attacks and thus enable fast transaction confirmations using the security guarantees of Trusted Execution Environments (TEEs). We achieve this by enforcing sign-once semantics that prevent the payer from reusing designated signing keys to sign more than one transaction. We also provide a way for the payee to verify whether a specific signing key is subject to sign-once semantics. The payee, however still receives the funds later, once the transaction is verified similarly to existing credit card payments. In this way, our solution reduces transaction confirmation times of blockchain-based cryptocurrencies and is also compatible with existing deployments since it does not require any modifications to the base protocol, peers, or miners. We designed and implemented a proof-of-concept of our solution using Intel SGX technology and integrated it with Copay, a popular Bitcoin wallet from BitPay. This thesis also presents the security evaluation of our system along with other possible extensions and enhancements. / De senaste åren har begäran efter sekretess och anonymitet för ekonomisk transaktioner sporrat tillväxten av elektroniska kontanter och kryptovalutor. Introducerandet av decentraliserade kryptovalutor, som t.ex. Bitcoin, har accelereratibruktagningen av dylika valutasystem. Digitala valutor är dock sårbara för dubbelspenderande (eng.double spending) eftersom digital information är lättare attreproducera. För att förhindra dubbelspenderande bokför Bitcoin valutatrans-aktioner i en distribuerad databas, den så kallade blockkedjan (eng.blockchain), som kan motstå förvanskling av bokförda transaktioner. Tiden som krävs för attgenerera nya block i Bitcoins blockkedja leder dock till en fördröjningen företransaktioner som skapas i databasen kan bekräftas. Denna fördröjning, som oftas varar kring en timme, är opraktisk för handel i verkliga världen och begränsardärför den allmänna spridningen av blockkedgebaserade kryptovalutor. I denna avhandlingen föreslår vi en lösningen som hindrar dubbelspenderandegenom att utnyttja säkerhetsgarantier hos anförtrodda exekveringsmiljöer (eng.Trusted Execution Environments). Vi åstadkommer detta genom att hindra beta-laren från att återanvända specifika kryptografiska nycklar för att digitalt signera flera transaktioner. Vi möjligjör också ett sätt för mottagaren att bekräfta ifall en kryptografisk underteckningsnyckel är skyddad på ovannämnda sätt. Mottagaren erhåller dock betalningen först senare, likt existerande kreditkortsbetalningar. Vår lösningen förminskar transaktionstiden för Bitcoin-betalningar på ett sätt som är kompatibelt med existerande användningssätt eftersom lösningen inte kräver modifikationer i grundläggande Bitcoin-protokollet. Vi utvecklade en prototyp av vår lösning genom att utnyttja Intel SGX teknologi och integrerade prototypen med CoPay, en popular plånboksapplikation för Bitcoin utveckald av företaget BitPay. Vi presenterar även en utvärdering av säkerheten i vårt system och beskriver möjliga utökningar och förbättringar. / <p>This thesis is part of Erasmus Mundus 2-Year Masters NordSecMob program. </p>

Nowadays cloud computing systems handle large amounts of data and process this data across different systems. It is essential to considering data security vulnerabilities and data protection. One means of decreasing security vulnerabilities is to partition the code into distinct modules and then isolate the execution of the code together with its data. Intel’s Software Guard Extension (SGX) provides security critical code isolation in an enclave. By isolating the code’s execution from an untrusted zone (an unprotected user platform), code integrity and confidentiality are ensured. Transport Layer Security (TLS) is responsible for providing integrity and confidentiality for communication between two entities. Several TLS libraries support cryptographic functions both for an untrusted zone and an enclave. Different TLS libraries have different performance when used with Intel’s SGX. It is desirable to use the best performance TLS library for specific cryptographic functions. This thesis describes a performance evaluation several popular TLS libraries performance on Intel SGX. Using the evaluation results and combining several different TLS libraries together, the thesis proposes a new solution to improve the performance of TLS libraries on Intel SGX. The performance is best when invoking the best specific TLS library based upon the data size – as there is a crossover in performance between the two best libraries. This solution also maintains the versatility of the existing cryptographic functions. / Numera hanterar molnberäkningssystem stora mängder data och bearbetar dessa data över olika system. Det är viktigt att ta itu med datasäkerhetsproblem och dataskydd. Ett sätt att minska säkerhetsproblem är att partitionera koden i olika moduler och sedan isolera kodens exekvering tillsammans med dess data. Intel’s Software Guard Extension (SGX) tillhandahåller säkerhetskritisk kodisolering i en enklav. Genom att isolera kodens körning från en otillförlitlig zon (en oskyddad användarplattform) säkerställs kodintegritet och sekretess. Transport Layer Security (TLS) ansvarar för att ge integritet och konfidentialitet för kommunikation mellan två enheter. Flera TLS-bibliotek stödjer kryptografiska funktioner både för en osäker zon och en enklav. Olika TLS-bibliotek har olika prestanda när de används med Intel’s SGX. Det är önskvärt att använda TLS-bibliotekets bästa prestanda för specifika kryptografiska funktioner. Denna avhandling beskriver en prestationsutvärdering av flera populära TLS-bibliotekens prestanda på Intel SGX. Genom att använda utvärderingsresultaten och kombinera flera olika TLS-bibliotek tillsammans, presenterar avhandlingen en ny design och lösning för att förbättra prestanda för TLS-bibliotek på Intel SGX. Den resulterande prestanda åberopar TLS-bibliotekets bästa prestanda inom en viss datastorlek samtidigt som krypteringsfunktionerna är mångsidiga.

As enterprises migrate their data to cloud infrastructure, they increasingly need a flexible, scalable, and secure marketplace for collaborative data creation, analysis, and exchange among enterprises. Security is a prominent research challenge in this context, with a specific question on how two mutually distrusting data owners can share their data. Confidential Computing helps address this question by allowing to perform data computation inside hardware-based Trusted Execution Environments (TEEs) which we refer to as enclaves, a secured memory that is allocated by CPU. Examples of hardware-based TEEs are Advanced Micro Devices (AMD)-Secure Encrypted Virtualization (SEV), Intel Software Guard Extensions (SGX) and Intel Trust Domain Extensions (TDX). Intel SGX is considered as the most popular hardware-based TEEs since it is widely available in processors targeting desktop and server platforms. Intel SGX can be programmed using Software Development Kit (SDK) as development framework and Library Operating Systems (Library OSes) as runtimes. However, communication with software in the enclave such as the Library OS through system calls may result in performance overhead. In this project, we design confidential data transactions among multiple users, using Intel SGX as TEE hardware and Occlum as Library OS. We implement the design by allowing two clients as data owners share their data to a server that owns Intel SGX capable platform. On the server side, we run machine learning model inference with inputs from both clients inside an enclave. In this case, we aim to evaluate Occlum as a memory-safe Library Operating System (OS) that enables secure and efficient multitasking on Intel SGX by measuring two evaluation aspects such as performance overhead and security benefits. To evaluate the measurement results, we compare Occlum with other runtimes: baseline Linux and Graphene-SGX. The evaluation results show that our design with Occlum outperforms Graphene-SGX by 4x in terms of performance. To evaluate the security aspects, we propose 11 threat scenarios potentially launched by both internal and external attackers toward the design in SGX platform. The results show that Occlum security features succeed to mitigate 10 threat scenarios out of 11 scenarios overall. / När företag migrerar sin data till molninfrastruktur behöver de i allt högre grad en flexibel, skalbar och säker marknadsplats för gemensam dataskapande, analys och utbyte mellan företag. Säkerhet är en framstående forskningsutmaning i detta sammanhang, med en specifik fråga om hur två ömsesidigt misstroende dataägare kan dela sina data. Confidential Computing hjälper till att ta itu med den här frågan genom att tillåta att utföra databeräkning i hårdvarubaserad TEEs som vi kallar enklaver, ett säkert minne som allokeras av CPU. Exempel på maskinvarubaserad TEEs är AMD-SEV, Intel SGX och Intel TDX. Intel SGX anses vara den mest populära maskinvarubaserade TEEs eftersom det finns allmänt tillgängligt i processorer som riktar sig mot stationära och serverplattformar. Intel SGX kan programmeras med hjälp av SDK som utvecklingsram och Library Operating System (Library OSes) som körtid. Kommunikation med programvara i enklaven, till exempel Library OS via systemanrop, kan dock leda till prestandakostnader. I det här projektet utformar vi konfidentiella datatransaktioner mellan flera användare, med Intel SGX som TEE-hårdvara och Occlum som Library OS. Vi implementerar designen genom att låta två klienter som dataägare dela sina data till en server som äger Intel SGX-kompatibel plattform. På serversidan kör vi maskininlärningsmodell slutsats med ingångar från båda klienterna i en enklav. I det här fallet strävar vi efter att utvärdera Occlum som ett minnessäkert Library OS som möjliggör säker och effektiv multitasking på Intel SGX genom att mäta två utvärderingsaspekter som prestandakostnader och säkerhetsfördelar. För att utvärdera mätresultaten jämför vi Occlum med andra driftstider: baslinjen Linux och Graphene-SGX. Utvärderingsresultaten visar att vår design med Occlum överträffar Graphene-SGX av 4x när det gäller prestanda. För att utvärdera säkerhetsaspekterna föreslår vi elva hotscenarier som potentiellt lanseras av både interna och externa angripare mot designen i SGX-plattformen. Resultaten visar att Occlums säkerhetsfunktioner lyckas mildra 10 hotscenarier av 11 scenarier totalt.

Cloud computing has become a default choice for data processing by both large corporations and individuals due to its economy of scale and ease of system management. However, the question of trust and trustoworthy computing inside the Cloud environments has been long neglected in practice and further exacerbated by the proliferation of AI and its use for processing of sensitive user data. Attempts to implement the mechanisms for trustworthy computing in the cloud have previously remained theoretical due to lack of hardware primitives in the commodity CPUs, while a combination of Secure Boot, TPMs, and virtualization has seen only limited adoption. The situation has changed in 2016, when Intel introduced the Software Guard Extensions (SGX) and its enclaves to the x86 ISA CPUs: for the first time, it became possible to build trustworthy applications relying on a commonly available technology. However, Intel SGX posed challenges to the practitioners who discovered the limitations of this technology, from the limited support of legacy applications and integration of SGX enclaves into the existing system, to the performance bottlenecks on communication, startup, and memory utilization. In this thesis, our goal is enable trustworthy computing in the cloud by relying on the imperfect SGX promitives. To this end, we develop and evaluate solutions to issues stemming from limited systems support of Intel SGX: we investigate the mechanisms for runtime support of POSIX applications with SCONE, an efficient SGX runtime library developed with performance limitations of SGX in mind. We further develop this topic with FFQ, which is a concurrent queue for SCONE's asynchronous system call interface. ShieldBox is our study of interplay of kernel bypass and trusted execution technologies for NFV, which also tackles the problem of low-latency clocks inside enclave. The two last systems, Clemmys and T-Lease are built on a more recent SGXv2 ISA extension. In Clemmys, SGXv2 allows us to significantly reduce the startup time of SGX-enabled functions inside a Function-as-a-Service platform. Finally, in T-Lease we solve the problem of trusted time by introducing a trusted lease primitive for distributed systems. We perform evaluation of all of these systems and prove that they can be practically utilized in existing systems with minimal overhead, and can be combined with both legacy systems and other SGX-based solutions. In the course of the thesis, we enable trusted computing for individual applications, high-performance network functions, and distributed computing framework, making a <vision of trusted cloud computing a reality.

Organizations in highly regulated industries have an increasing need to protect their intellectual assets, because Advanced Persistent Threat (APT) entities are capable of using supply chain attacks to bypass traditional defenses. This work investigates the feasibility of preventing supply chain attacks by isolating the build environment of the software using hardware isolation. Specifically, this work analyzes the extent to which the Intel SGX can guarantee the integrity and authenticity of software produced in Highly Regulated Environments. A theoretical evaluation using assurance cases shows that a hardware isolation approach has the potential to guarantee the integrity and authenticity of the produced software. Security weaknesses in Intel SGX significantly limit the confidence in its ability to secure the build environment. Directions for future work to secure a build environment with a hardware isolation approach are suggested. Most importantly, the guarantees from hardware isolation should be improved, suggestively by choosing a more secure hardware isolation solution, and a proof-of-concept of the approach should be implemented. / Organisationer i mycket reglerade industrier har ett ökat behov av att skydda sina intellektuella tillgångar, eftersom avancerade långvariga hot (APT) har förmågan att använda sig av distributionskedjeattacker för att ta sig förbi existerande skydd. Det här arbetet undersöker möjligheten att skydda sig mot distributionskedjeattacker genom att isolera mjukvarans byggmiljö med hjälp av hårdvaruisolering. Specifikt analyseras till vilken grad Intel SGX kan garantera integriteten och autenticiteten av mjukvara som produceras i mycket reglerade miljöer. En teoretisk evaluering genom assurans visar att hårdvaruisolering har möjligheten att garantera integriteten och autenticiteten hos den producerade mjukvaran. Säkerhetsbrister i Intel SGX begränsar i hög grad förtroendet för dess förmåga att säkra byggmiljön. För vidare forskning föreslås att garantierna från hårdvaruisolering förbättras, förslagsvis genom att välja säkrare hårdvaruisoleringslösningar, samt att en prototyp av lösningen implementeras.

The aim of this thesis is to create a concept of semi-centralized cryptocurrency that supports external interoperability. It is assumed that semi-centralized cryptocurrency is the future of cryptocurrencies in the banking sector, because even at the cost of partial centralization, the concept brings the benefits of a decentralized ledger. Since the simultaneous deployment of their own cryptocurrencies by various central authorities, such as central bank, it is necessary to establish a communication protocol for interbank transactions. The work is thus focused on extending the existing Aquareum solution with an interoperability protocol.