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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
211

Architectural support for improving security and performance of memory sub-systems

Yan, Chenyu 17 November 2008 (has links)
This thesis explores architectural level optimizations to make secure systems more efficient, secure and affordable. It extends prior work for secure architecture in several areas. It proposes a new combined memory encryption and authentication scheme which uses very small on-chip storage area and incurs much less performance overhead compared with prior work. In addition, the thesis studies the issues of applying architectural support for data security to distributed shared memory systems. It presents a scheme which is scalable with large-scale systems and only introduces negligible performance overhead for confidentiality and integrity protection. Furthermore, the thesis also investigates another source of reducing performance overhead in secure systems through optimizing on-chip caching schemes and minimizing off-chip communications.
212

A Modular architecture for Cloud Federation

Panjwani, Rizwan 21 December 2015 (has links)
Cloud Computing is the next step in the evolution of the Internet. It provides seemingly unlimited computation and storage resources by abstracting the networking, hardware, and software components underneath. However, individual cloud service providers do not have unlimited resources to offer. Some of the tasks demand computational resources that these individual cloud service providers can not fulfill themselves. In such cases, it would be optimal for these providers to borrow resources from each other. The process where different cloud service providers pool their resources is called Cloud Federation. There are many aspects to Cloud Federation such as access control and interoperability. Access control ensures that only the permitted users can access these federated resources. Interoperability enables the end-user to have a seamless experience when accessing resources on federated clouds. In this thesis, we detail our project named GENI-SAVI Federation, in which we federated the GENI and SAVI cloud systems. We focus on the access control portion of the project while also discussing the interoperability aspect of it. / Graduate / 0984 / panjwani.riz@gmail.com
213

Scan me – Ökad säkerhet med multifactor authentication : En undersökning om effekten vid ökad säkerhet i digitala identifierare / Scan me - Increased security with multifactor authentication : A study of the effect when the security increases in digital identifiers

Borgman, Isabelle January 2016 (has links)
Följande kandidatuppsats undersöker en applikation utifrån tre faktorer: säkerhet, användbarhet och funktionalitet. Arbetet tar fram en prototyp på en identifieringsapplikation som använder sig av QR-koder för att identifiera personer. Identifieringsprocessen är tänkt att fungera i t.ex. en insläppningskö på en pub. QR-koden finns i gästens mobil och dörrvakten använder den framtagna prototypen på en surfplatta eller smartphone för att scanna av gästens QR-kod. Syftet är att undersöka hur användbarheten och funktionaliteten påverkas i en applikation när det läggs till en faktor för att öka säkerheten. Detta undersöks genom ett användartest där 8 testpersoner får testa den framtagna prototypen och ge kommentarer både utifrån en gästs och en dörrvakts perspektiv. Resultaten visar på att användbarheten dras ner något i samband med att säkerheten ökar. Identifiering med hjälp av QR-läsaren tar ungefär 4 sekunder längre än vad det gör att identifiera med den vanliga metoden, d.v.s jämföra ett ID-kort med ett medlemskort. Funktionaliteten ökar i systemet eftersom att det läggs till funktionalitet för att scanna av en QR-kod och jämföra informationen ur den med en databas. Prototypen som har tagits fram i denna kandidatuppsats har utvecklingsmöjligheter och kan användas i andra sammanhang och i andra miljöer; prototypen skulle exempelvis fungera lika bra i ett affärssammanhang där affären kan ersätta sina fysiska medlemskort med en QR-kod och en avläsare för att ge sina kunder förmåner. / The following bachelor thesis examines an application based on three factors: security, usability and functionality. The work presents a prototype of an identification application that uses QR codes to identify a person. The identification process is supposed to work in eg a line to a pub. The QR-code is in the guest's mobile and the doorman uses the prototype, which this thesis presents, on a tablet or smartphone and scan the guest's QR code. The aim is to investigate how the usability and functionality is affected in an application when it is added a factor that increases the apps security. This is examined through a user test where 8 test subjects will test the developed prototype and provide feedback both from a guest and a doormans perspective. The results show that the usability decreases while the security increases. The identification with the QR reader takes about 4 seconds longer than it does to identify with the usual method, i.e. comparing an ID card with a membership card. The functionality in the system increases because we add the functionality to scan a QR-code and compare it's information with a database. The prototype that has been developed in this bachelor thesis has development potential and can be used in other contexts and in other environments; for example the prototype would work equally well in a business context in which the business can replace their membership card with a QR code and a reader to give their customers benefits.
214

Použití smart-karet v moderní kryptografii / The use of smart-cards in modern cryptography

Kočíř, Michal January 2013 (has links)
This thesis discusses the general use of smart cards in MULTOS in cryptographic applications. At first is described two types of authentication - the authentication by the subject with focusing on authenticators and the authentication by the knowledge. Furthermore there is the description of the anonymous authentication and attribute authentization. This is followed by a description of smart cards with a focus on MULTOS cards. There is also performed analysis of programmable smart cards .NET, JavaCard and MULTOS. Practical part is focused on the implementation of an authentication scheme, which is being developed at FEEC. The communication of authentication protocol is between the MULTOS card and reader connected to a PC. The protocol is composed of cryptographic functions such as random number generation, hash function, modular exponentiation, modular multiplication and difference of large numbers. It was also implemented the measurement of specific applications.
215

Secure Access for Public Clients to Web API:s with Minimum Performance Loss / Säker åtkomst för publika klienter mot Web API:er med minimal prestandaförlust

Maan, Narbir Singh, Hanchi, Hamza January 2014 (has links)
A lot of information nowadays is made available through Web APIs on the Internet and without security and encryption; it is very easy for malicious users to access confidential information. The goal was to find out what different mechanisms that are available for providing a safe communication with a web API from web clients and mobile applications with little as possible impact on the performance. Learning, implementing and maintaining the mechanisms are also im- portant aspects looked at in the evaluation. Many mechanisms are available for use to secure the communication but not all are suitable for public clients. The suitable mechanisms are Digest authentication and OAuth 2.0. The chosen mechanisms were developed, tested and evaluated in regard to safety, performance impact and usabil- ity from a company perspective. The authentication and authorization mechanism, which was the most suitable, was OAuth 2.0as it has least impact on performance and better security features than the other mechanisms. / Mycket information finns numera tillgänglig via Web API:er på Internet och utan säkerhet och kryptering är det mycket lätt att illvilliga personer får tillgång till konfidentiellinformation. Målet är att ta reda på vilka olika säkerhetsmekanismer som finns tillgängliga för att tillhandahålla en säker kommunikation med ett Web API från webbklienter och mobila applikationer med så liten påverkan på prestanda. Kunskapsinhämtning, utveckling och underhållandet av lösningar är också viktiga aspeketer som tittats på vid utvärderingen av mekanismerna. Flera mekanismer finns att använda sig av för att säkra kommunkationen men de lämpliga mekanismerna för publika klienter är Digest Authentication och OAuth 2.0. De utvalda mekanismerna har utvecklats, testats, utvärderats med avseende på säkerhet, påverkan på prestanda och användbarhet utifrån ett företags perspektiv. Autentiserings- och behörighets-mekanismen som blev den utvalda var OAuth 2.0 då den har minst påverkan på prestandan och bättre säkerhets egenskaper än de andra mekanismerna.
216

A Digital Identity Management System

Phiri, Jackson January 2007 (has links)
>Magister Scientiae - MSc / The recent years have seen an increase in the number of users accessing online services using communication devices such as computers, mobile phones and cards based credentials such as credit cards. This has prompted most governments and business organizations to change the way they do business and manage their identity information. The coming of the online services has however made most Internet users vulnerable to identity fraud and theft. This has resulted in a subsequent increase in the number of reported cases of identity theft and fraud, which is on the increase and costing the global industry excessive amounts. Today with more powerful and effective technologies such as artificial intelligence, wireless communication, mobile storage devices and biometrics, it should be possible to come up with a more effective multi-modal authentication system to help reduce the cases of identity fraud and theft. A multi-modal digital identity management system IS proposed as a solution for managing digital identity information in an effort to reduce the cases of identity fraud and theft seen on most online services today. The proposed system thus uses technologies such as artificial intelligence and biometrics on the current unsecured networks to maintain the security and privacy of users and service providers in a transparent, reliable and efficient way. In order to be authenticated in the proposed multi-modal authentication system, a user is required to submit more than one credential attribute. An artificial intelligent technology is used to implement a technique of information fusion to combine the user's credential attributes for optimum recognition. The information fusion engine is then used to implement the required multi-modal authentication system.
217

Consensus algorithms for adding blocks to private blockchains in IIoT networks : Comparison of two Proof-of-Authentication implementations on IIoT hardware / Konsensusalgoritmer för att lägga till block till privata blockkedjor i IIoT-nätverk : Jämförelse av två Proof-of-Authentication-implementeringar på IIoT-hårdvara

Juvencius, Kamile, Ankarberg, Therése January 2021 (has links)
The Internet of Things (IoT) market is growing by the day and there are no signs of stagnation. As the market grows, it becomes all the more important to address security concerns. A major security issue of IoT is that the devices usually send their collected data to a centralized entity, creating a single point of failure. A solution to this is decentralization. Blockchain technology offers not only decentralization, but also immutability and data integrity. In blockchain, it is the consensus algorithm that is used to coordinate the devices and achieve unanimity within the network. These consensus algorithms are generally computationally expensive and are typically not compatible with IoT devices, due to the limited resources of the devices and the need to send data in real-time. This study implemented and compared two versions of the consensus algorithms Proof of Authentication, which are designed specifically for IoT devices. The results show that one algorithm is considerably faster than the other, however, a fair comparison could not be made due to unforeseeable difficulties with the Industrial IoT(IIoT) device used in this study. This study concluded that algorithm 1 is most likely a viable choice as a consensus algorithm for IIoT networks. No conclusion could be drawn for algorithm 2 due to the unsatisfactory implementation because of the limitations of the devices used in this study. / Sakernas internet (IoT)-marknaden växer dagligen och det finns inga tecken på stagnation. När marknaden växer blir det desto viktigare att hantera säkerhetsproblem. En viktig säkerhetsfråga för IoT är att enheterna vanligtvis skickar sin insamlade data till en central enhet, vilket skapar en enda svag länk. En lösning på detta är decentralisering. Blockchain-tekniken erbjuder inte bara decentralisering utan också oföränderlighet och dataintegritet. I blockchain är det konsensusalgoritmen som används för att samordna enheterna i nätverket och uppnå enhällighet. Dessa algoritmer är i allmänhet beräkningsmässigt dyra och är vanligtvis inte kompatibla med IoT-enheter på grund av enheternas begränsade resurser och behov av att skicka data i realtid. Denna studie implementerade och jämförde två konsensusalgoritmer utformade speciellt för IoT-enheter. Resultaten visar att ena algoritmen är betydligt snabbare än den andra, men en rättvis jämförelse kunde inte göras på grund av oförutsägbara svårigheter med Industriella IoT (IIoT)-enheten som användes i denna studie. Denna studie drog slutsatsen att algoritm 1 sannolikt är ett genomförbart val som en konsensusalgoritm för IIoT-nätverk. Ingen slutsats kunde dras för algoritm 2 på grund av det otillfredsställande genomförandet på grund av begränsningarna för enheterna som används i denna studie.
218

SSASy: A Self-Sovereign Authentication Scheme

Manzi, Olivier January 2023 (has links)
Amidst the wild west of user authentication, this study introduces a new sheriff in town: the Self-Sovereign Authentication Scheme (SSASy). Traditional authentication methods, like passwords, are often fraught with usability and security concerns, leading users to find workaround ways that compromise the intended security. Federated Identities (FI) offer a convenient alternative, yet, they infringe on users' sovereignty over their identity and lead to privacy concerns. To address these challenges, this study proposes SSASy, which leverages cryptography and browser technology to provide a sovereign, usable, and secure alternative to the existing user authentication schemes. The proposal, which is a proof-of-concept, is comprised of a core library, which provides the authentication protocol to developers, and a browser extension that simplifies the authentication process for users. SSASy is available as an open-source project on GitHub for practical demonstration on multiple browser stores, bringing our theoretical study into the realm of tangible, real-world application. SSASy is evaluated and compared to existing authentication schemes using the "Usability-Deployability-Security" (UDS) framework. The results demonstrate that, although other authentication schemes may excel in a specific dimension, SSASy delivers a more balanced performance across the three dimensions which makes it a promising alternative.
219

Session hijacking attacks in wireless local area networks

Onder, Hulusi 03 1900 (has links)
Approved for public release, distribution is unlimited / Wireless Local Area Network (WLAN) technologies are becoming widely used since they provide more flexibility and availability. Unfortunately, it is possible for WLANs to be implemented with security flaws which are not addressed in the original 802.11 specification. IEEE formed a working group (TGi) to provide a complete solution (code named 802.11i standard) to all the security problems of the WLANs. The group proposed using 802.1X as an interim solution to the deficiencies in WLAN authentication and key management. The full 802.11i standard is expected to be finalized by the end of 2004. Although 802.1X provides a better authentication scheme than the original 802.11 security solution, it is still vulnerable to denial-of-service, session hijacking, and man-in-the- middle attacks. Using an open-source 802.1X test-bed, this thesis evaluates various session hijacking mechanisms through experimentation. The main conclusion is that the risk of session hijacking attack is significantly reduced with the new security standard (802.11i); however, the new standard will not resolve all of the problems. An attempt to launch a session hijacking attack against the new security standard will not succeed, although it will result in a denial-of-service attack against the user. / Lieutenant Junior Grade, Turkish Navy
220

Security and usability of authentication by challenge questions in online examination

Ullah, Abrar January 2017 (has links)
Online examinations are an integral component of many online learning environments and a high-stake process for students, teachers and educational institutions. They are the target of many security threats, including intrusion by hackers and collusion. Collu-sion happens when a student invites a third party to impersonate him/her in an online test, or to abet with the exam questions. This research proposed a profile-based chal-lenge question approach to create and consolidate a student's profile during the learning process, to be used for authentication in the examination process. The pro-posed method was investigated in six research studies using a usability test method and a risk-based security assessment method, in order to investigate usability attributes and security threats. The findings of the studies revealed that text-based questions are prone to usability issues such as ambiguity, syntactic variation, and spelling mistakes. The results of a usability analysis suggested that image-based questions are more usable than text-based questions (p < 0.01). The findings identified that dynamic profile questions are more efficient and effective than text-based and image-based questions (p < 0.01). Since text-based questions are associated with an individual's personal information, they are prone to being shared with impersonators. An increase in the numbers of chal-lenge questions being shared showed a significant linear trend (p < 0.01) and increased the success of an impersonation attack. An increase in the database size decreased the success of an impersonation attack with a significant linear trend (p < 0.01). The security analysis of dynamic profile questions revealed that an impersonation attack was not successful when a student shared credentials using email asynchronously. However, a similar attack was successful when a student and impersonator shared information in real time using mobile phones. The response time in this attack was significantly different when a genuine student responded to his challenge questions (p < 0.01). The security analysis revealed that the use of dynamic profile questions in a proctored exam can influence impersonation and abetting. This view was supported by online programme tutors in a focus group study.

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