The definition of Electronic commerce is the use of electronic transmission mediums to engage in the exchange, including buying and selling, of products and services requiring transportation, either physically or digitally, from location to location. Electronic commerce systems, including mobile e-commerce, are widely used since 1990. The number of world-wide Internet users tripled between 1993 and 1995 to 60 million, and by 2000 there were 250 million users. More than one hundred countries have Internet access. Electronic commerce, especial mobile e-commerce systems, allows their users to access a large set of traditional (for example, voice communications) and contemporary (for example, e-­shop) services without being tethered to one particular physical location. With the increasing use of electronic service systems for security sensitive application (for example, e-shop) that can be expected in the future, the provision of secure services becomes more important. The dynamic mobile environment is incompatible with static security services. Electronic service access across multiple service domains, and the traditional access mechanisms rely on cross-domain authentication using roaming agreements starting home location. Cross-domain authentication involves many complicated authentication activities when the roam path is long. This limits future electronic commerce applications. Normally, there are three participants in an electronic service. These are users, service providers, and services. Some services bind users and service providers as well as services such as flight services; other services do not bind any participants, for instance by using cash in shopping services, everyone can use cash to buy anything in shops. Hence, depending on which parts are bound, there are different kinds of electronic services. However, there is no scheme to provide a solution for all kinds of electronic services. Users have to change service systems if they want to apply different kind of electronic services on the Internet. From the consumer's point of view, users often prefer to have a total solution for all kinds of service problems, some degree of anonymity with no unnecessary cross authentications and a clear statement of account when shopping over the Internet. There are some suggested solutions for electronic service systems, but the solutions are neither total solution for all kinds of services nor have some degree of anonymity with a clear statement of account. In our work, we build a bridge between existing technologies and electronic service theory such as e-payment, security and so on. We aim to provide a foundation for the improvement of technology to aid electronic service application. As validation, several technologies for electronic service system design have been enhanced and improved in this project. To fix the problems mentioned above, we extend our idea to a ticket based access service system. The user in the above electronic service system has to pay when s/he obtains service. S/He can pay by traditional cash (physical cash), check, credit or electronic cash. The best way to pay money for goods or services on the Internet is using electronic cash. Consumers, when shopping over the Internet, often prefer to have a high level of anonymity with important things and a low level with general one. The ideal system needs to provide some degree of anonymity for consumers so that they cannot be traced by banks. There are a number of proposals for electronic cash systems. All of them are either too large to manage or lack flexibility in providing anonymity. Therefore, they are not suitable solutions for electronic payment in the future. We propose a secure, scalable anonymity and practical payment protocol for Internet purchases. The protocol uses electronic cash for payment transactions. In this new protocol, from the viewpoint of banks, consumers can improve anonymity if they are worried about disclosure of their identities. An agent, namely anonymity provider agent provides a higher anonymous certificate and improves the security of the consumers. The agent will certify re-encrypted data after verifying the validity of the content from consumers, but with no private information of the consumers required. With this new method, each consumer can get the required anonymity level. Electronic service systems involve various subsystems such as service systems, payment systems, and management systems. Users and service providers are widely distributed and use heterogeneous catalog systems. They are rapidly increasing in dynamic environments. The management of these service systems will be very complex. Whether systems are successful or not depends on the quality of their management. To simplify the management of e-commerce systems \cite{Sandhu97}, we discuss role based access control management. We define roles and permissions in the subsystems. For example, there are roles TELLER, AUDITOR, MANAGER and permissions teller (account operation), audit operation, managerial decision in a bank system. Permissions are assigned to roles such as permission teller is assigned to role TELLER. People (users) employed in the bank are granted roles to perform associated duties. However, there are conflicts between various roles as well as between various permissions. These conflicts may cause serious security problems with the bank system. For instance, if permissions teller and audit operation are assigned to a role, then a person with this role will have too much privilege to break the security of the bank system. Therefore, the organizing of relationships between users and roles, roles and permissions currently requires further development. Role based access control (RBAC) has been widely used in database management and operating systems. In 1993, the National Institute of Standards and Technology (NIST) developed prototype implementations, sponsored external research, and published formal RBAC models. Since then, many RBAC practical applications have been implemented, because RBAC has many advantages such as reducing administration cost and complexity. However, there are some problems which may arise in RBAC management. One is related to authorization granting process. For example, when a role is granted to a user, this role may conflict with other roles of the user or together with this role; the user may have or derive a high level of authority. Another is related to authorization revocation. For instance, when a role is revoked from a user, the user may still have the role. To solve these problems, we present an authorization granting algorithm, and weak revocation and strong revocation algorithms that are based on relational algebra. The algorithms check conflicts and therefore help allocate the roles and permissions without compromising the security in RBAC. We describe the applications of the new algorithms with an anonymity scalable payment scheme. In summary, this thesis has made the following major contributions in electronic service systems: 1. A ticket based global solution for electronic commerce systems; A ticket based solution is designed for different kinds of e-services. Tickets provide a flexible mechanism and users can check charges at anytime. 2. Untraceable electronic cash system; An untraceable e-cash system is developed, in which the bank involvement in the payment transaction between a user and a receiver is eliminated. Users remain anonymous, unless she/he spends a coin more than once. 3. A self-scalable anonymity electronic payment system; In this payment system, from the viewpoint of banks, consumers can improve anonymity if they are worried about disclosure of their identities. Each consumer can get the required anonymity level. 4. Using RBAC to manage electronic payment system; The basic structure of RBAC is reviewed. The challenge problems in the management of RBAC with electronic payment systems are analysed and how to use RBAC to manage electronic payment system is proposed. 5. The investigation of recovery algorithms for conflicting problems in user-role assignments and permission-role assignments. Formal authorization allocation algorithms for role-based access control have developed. The formal approaches are based on relational structure, and relational algebra and are used to check conflicting problems between roles and between permissions.

MHRD PhD scholarship / With Multiprocessor Systems-on-Chips (MPSoCs) pervading our lives, security issues are emerging as a serious problem and attacks against these systems are becoming more critical and sophisticated. We have designed and implemented different hardware based solutions to ensure security of an MPSoC. Security assisting modules can be implemented at different abstraction levels of an MPSoC design. We propose solutions both at circuit level and system level of abstractions. At the VLSI circuit level abstraction, we consider the problem of presence of noise voltage in input signal coming from outside world. This noise voltage disturbs the normal circuit operation inside a chip causing false logic reception. If the disturbance is caused intentionally the security of a chip may be compromised causing glitch/transient attack. We propose an input receiver with hysteresis characteristic that can work at voltage levels between 0.9V and 5V. The circuit can protect the MPSoC from glitch/transient attack. At the system level, we propose solutions targeting Network-on-Chip (NoC) as the on-chip communication medium. We survey the possible attack scenarios on present-day MPSoCs and investigate a new attack scenario, i.e., router attack targeted toward NoC enabled MPSoC. We propose different monitoring-based countermeasures against routing table-based router attack in an MPSoC having multiple Trusted Execution Environments (TEEs). Software attacks, the most common type of attacks, mainly exploit vulnerabilities like buffer overflow. This is possible if proper access control to memory is absent in the system. We propose four hardware based mechanisms to implement Role Based Access Control (RBAC) model in NoC based MPSoC.

Os recentes avanços nas tecnologias de comunicação e computação viabilizaram o pronto acesso às informações do prontuário eletrônico do paciente (PEP). O potencial de difusão de informações clínicas resultante suscita preocupações acerca da priva-cidade do paciente e da confidencialidade de seus dados. As normas presentes na legislação dispõem que o conteúdo do prontuário deve ser sigiloso, não cabendo o acesso a ele sem a prévia autorização do paciente, salvo quando necessário para be-neficiá-lo. Este trabalho propõe o MACA, um modelo de autorização contextual para o controle de acesso baseado em papéis (CABP) que contempla requisitos de limita-ção de acesso ao PEP em ambientes abertos e distribuídos. O CABP regula o acesso dos usuários ao PEP com base nas funções (papéis) que eles exercem numa organi-zação. Uma autorização contextual usa informações ambientais disponíveis durante o acesso para decidir se um usuário tem o direito e a necessidade de acessar um re-curso do PEP. Isso confere ao MACA flexibilidade e poder expressivo para estabele-cer políticas de acesso ao PEP e políticas administrativas para o CABP que se adap-tam à diversidade ambiental e cultural das organizações de saúde. O MACA ainda permite que os componentes do PEP utilizem o CABP de forma transparente para o usuário final, tornando-o mais fácil de usar quando comparado a outros modelos de CABP. A arquitetura onde a implementação do MACA foi integrada adota o serviço de diretórios LDAP (Lightweight Directory Access Protocol), a linguagem de pro-gramação Java e os padrões CORBA Security Service e Resource Access Decision Fa-cility. Com esses padrões abertos e distribuídos, os componentes heterogêneos do PEP podem solicitar serviços de autenticação de usuário e de autorização de acesso de modo unificado e coerente a partir de múltiplas plataformas. A implementação do MACA ainda tem a vantagem de ser um software livre, de basear-se em componen-tes de software sem custos de licenciamento e de apresentar bom desempenho para as demandas de acesso estimadas. Por fim, a utilização rotineira do MACA no con-trole de acesso ao PEP do InCor-HC.FMUSP, por cerca de 2000 usuários, evidenciam a exeqüibilidade do modelo, da sua implementação e da sua aplicação prática em casos reais. / The recent advances in computing and communication technologies allowed ready access to the electronic patient record (EPR) information. High availability of clinical information raises concerns about patients privacy and data confidentiality of their data. The legal regulation mandates the confidentiality of EPR contents. Everyone has to be authorized by the patients to access their EPR, except when this access is necessary to provide care on their behalf. This work proposes MACA, a contextual authorization model for the role-based access control (RBAC) that considers the ac-cess restrictions requirements for the EPR in open and distributed environments. RBAC regulates user’s access to EPR based on organizational functions (roles). Con-textual authorizations use environmental information available at access time, like user/patient relationship, in order to decide whether a user is allowed to access an EPR resource. This gives flexibility and expressive power to MACA, allowing one to establish access policies for the EPR and administrative policies for the RBAC that considers the environmental and cultural diversity of healthcare organizations. MACA also allows EPR components to use RBAC transparently, making it more user friendly when compared with other RBAC models. The implementation of MACA architecture uses the LDAP (Lightweight Directory Access Protocol) directory server, the Java programming language and the standards CORBA Security Service and Re-source Access Decision Facility. Thus, heterogeneous EPR components can request user authentication and access authorization services in a unified and coherent way across multiple platforms. MACA implementation complies with free software pol-icy. It is based on software components without licensing costs and it offers good performance for the estimated access demand. Finally, the daily use of MACA to control the access of about 2000 users to the EPR at InCor-HC.FMUSP shows the feasibility of the model, of its implementation and the effectiveness of its practical application on real cases.

Os recentes avanços nas tecnologias de comunicação e computação viabilizaram o pronto acesso às informações do prontuário eletrônico do paciente (PEP). O potencial de difusão de informações clínicas resultante suscita preocupações acerca da priva-cidade do paciente e da confidencialidade de seus dados. As normas presentes na legislação dispõem que o conteúdo do prontuário deve ser sigiloso, não cabendo o acesso a ele sem a prévia autorização do paciente, salvo quando necessário para be-neficiá-lo. Este trabalho propõe o MACA, um modelo de autorização contextual para o controle de acesso baseado em papéis (CABP) que contempla requisitos de limita-ção de acesso ao PEP em ambientes abertos e distribuídos. O CABP regula o acesso dos usuários ao PEP com base nas funções (papéis) que eles exercem numa organi-zação. Uma autorização contextual usa informações ambientais disponíveis durante o acesso para decidir se um usuário tem o direito e a necessidade de acessar um re-curso do PEP. Isso confere ao MACA flexibilidade e poder expressivo para estabele-cer políticas de acesso ao PEP e políticas administrativas para o CABP que se adap-tam à diversidade ambiental e cultural das organizações de saúde. O MACA ainda permite que os componentes do PEP utilizem o CABP de forma transparente para o usuário final, tornando-o mais fácil de usar quando comparado a outros modelos de CABP. A arquitetura onde a implementação do MACA foi integrada adota o serviço de diretórios LDAP (Lightweight Directory Access Protocol), a linguagem de pro-gramação Java e os padrões CORBA Security Service e Resource Access Decision Fa-cility. Com esses padrões abertos e distribuídos, os componentes heterogêneos do PEP podem solicitar serviços de autenticação de usuário e de autorização de acesso de modo unificado e coerente a partir de múltiplas plataformas. A implementação do MACA ainda tem a vantagem de ser um software livre, de basear-se em componen-tes de software sem custos de licenciamento e de apresentar bom desempenho para as demandas de acesso estimadas. Por fim, a utilização rotineira do MACA no con-trole de acesso ao PEP do InCor-HC.FMUSP, por cerca de 2000 usuários, evidenciam a exeqüibilidade do modelo, da sua implementação e da sua aplicação prática em casos reais. / The recent advances in computing and communication technologies allowed ready access to the electronic patient record (EPR) information. High availability of clinical information raises concerns about patients privacy and data confidentiality of their data. The legal regulation mandates the confidentiality of EPR contents. Everyone has to be authorized by the patients to access their EPR, except when this access is necessary to provide care on their behalf. This work proposes MACA, a contextual authorization model for the role-based access control (RBAC) that considers the ac-cess restrictions requirements for the EPR in open and distributed environments. RBAC regulates user’s access to EPR based on organizational functions (roles). Con-textual authorizations use environmental information available at access time, like user/patient relationship, in order to decide whether a user is allowed to access an EPR resource. This gives flexibility and expressive power to MACA, allowing one to establish access policies for the EPR and administrative policies for the RBAC that considers the environmental and cultural diversity of healthcare organizations. MACA also allows EPR components to use RBAC transparently, making it more user friendly when compared with other RBAC models. The implementation of MACA architecture uses the LDAP (Lightweight Directory Access Protocol) directory server, the Java programming language and the standards CORBA Security Service and Re-source Access Decision Facility. Thus, heterogeneous EPR components can request user authentication and access authorization services in a unified and coherent way across multiple platforms. MACA implementation complies with free software pol-icy. It is based on software components without licensing costs and it offers good performance for the estimated access demand. Finally, the daily use of MACA to control the access of about 2000 users to the EPR at InCor-HC.FMUSP shows the feasibility of the model, of its implementation and the effectiveness of its practical application on real cases.

Access control is a crucial aspect of cybersecurity, and Role Based Access Control (RBAC) is a typical framework for controlling the access to specific resources. However, in the context of Smart Grids, the usual authentication solution of using a trusted identity provider might not be possible to provide authentication of a user, as systems cannot rely on external services. This, in addition to devices in a substation being usually strictly controlled, means that having an RBAC limited to a desktop application can be necessary. Moreover, the cost of adding additional layers of security needs to be considered too, as the cost of adding specific features can vary significantly. This thesis thus looks into the existing solutions for desktop applications in substations, explains their viability and implements an RBAC system using Group Nesting in Windows user management, in the context of a configuration loading application on a main computer in a substation. It is then used to evaluate the cost of this new solution, in terms of maintainability, usability and flexibility, compared to the gained security. This is done by using static analysis of both codebases, and evaluation of usability and security. It shows that security can be added for a reasonable cost using Group Nesting in Smart Grids if the focus is to delegate some tasks to the directory, improving on the security of the application and the system as a whole. / Åtkomstkontroll är en viktig aspekt av cybersäkerhet, och rollbaserad åtkomstkontroll (RBAC) är ett typiskt ramverk för att kontrollera åtkomsten till specifika resurser. I smarta nät kan det dock hända att den vanliga autentiseringslösningen med en betrodd identitetsleverantör inte är tillräcklig för att autentisera en användare, eftersom systemen inte kan förlita sig på externa tjänster. Detta, förutom att enheterna i en transformatorstation vanligtvis är strikt kontrollerade, innebär att det kan vara nödvändigt att ha en RBAC som är begränsad till en datorapplikation. Dessutom måste kostnaden för att lägga till ytterligare säkerhetslager också beaktas, eftersom kostnaden för att lägga till specifika funktioner kan variera avsevärt. Denna avhandling omfattar därför dels undersökning av de befintliga lösningarna för datorapplikation i transformatorstationer, dels redogörelse av genomförbarheten och dels implementeringen av ett RBAC-system. Implementationen använder funktionen Group Nesting i Windows-användarhantering och integrerades i en applikation för konfigurationsinläsning på en huvuddator i en transformatorstation. Därefter utvärderas kostnaden för denna nya lösning i fråga om underhållbarhet, användbarhet och flexibilitet i förhållande till den ökade säkerheten. Detta görs med hjälp av statisk analys av de båda mjukvarulösningarna och utvärdering av användbarhet och säkerhet. Det visar att säkerheten kan ökas till en rimlig kostnad med hjälp av Group Nesting i smarta nät, om fokus ligger på att delegera vissa uppgifter till en katalog, vilket förbättrar säkerheten i applikationen och systemet som helhet. / Le contrôle ’daccès est un aspect essentiel de la cybersécurité, et utiliser des rôles pour implémenter cela est souvent le modèle recommandé. Pour autant, dans le contexte des réseaux électriques intelligents, il ’nest pas toujours possible de posséder un parti tiers fiable qui puisse faire autorité car il ne faut pas dépendre de systèmes extérieurs. ’Cest particulièrement vrai dans une sous-station où les ordinateurs connectés ont un rôle strictement défini. Ainsi il peut être nécessaire ’davoir un système de contrôle ’daccès basé sur les rôles (RBAC, Role-Based Access Control) uniquement contenu sur un ordinateur. Il faut de plus pouvoir estimer le coût de cette sécurité supplémentaire. Ce rapport évalue les solutions existantes dans cette situation et leur viabilité, et implémente un RBAC grâce à ’limbrication de groupe ’dutilisateur Windows, pour une application desktop pour le chargement de configuration pour l´ordinateur central ’dune sous-station. Cette implémentation est ensuite utilisée pour estimer les coûts associés à ’lajout ’dun RBAC en termes de maintenabilité, ’dutilisabilité et de flexibilité par rapport aux gains de sécurité. Cela est fait à travers des outils ’danalyse statique sur le code avant et après implémentation et ’dautres techniques ’danalyse de la sécurité et de la maintenabilité. Cela permet de montrer que, avec ’limbrication de groupes, il est possible ’dobtenir un niveau de sécurité satisfaisant tout en limitant les coûts associés, grâce au fait de déléguer les fonctions de gestion ’dutilisateur à un système de directory (répertoire).