Cryptographic protocols for privacy-aware and secure e-commerce

Aquesta tesi tracta sobre la investigació i el desenvolupament de tecnologies de millora de la privadesa per a proporcionar als consumidors de serveis de comerç electrònic el control sobre quanta informació privada volen compartir amb els proveïdors de serveis. Fem servir tecnologies existents, així com tecnologies desenvolupades durant aquesta tesi, per a protegir als usuaris de la recoleció excessiva de dades per part dels proveïdors de serveis en aplicacions específiques. En particular, fem servir un nou esquema de signatura digital amb llindar dinàmic i basat en la identitat per a implementar un mecanisme d'acreditació de la mida d'un grup d'usuaris, que només revela el nombre d'integrants del grup, per a implementar descomptes de grup. A continuació, fem servir una nova construcció basada en signatures cegues, proves de coneixement nul i tècniques de generalització per implementar un sistema de descomptes de fidelitat que protegeix la privadesa dels consumidors. Per últim, fem servir protocols de computació multipart per a implementar dos mecanismes d'autenticació implícita que no revelen informació privada de l'usuari al proveïdor de serveis.Esta tesis trata sobre la investigación y desarrollo de tecnologías de mejora de la privacidad para proporcionar a los consumidores de servicios de comercio electrónico el control sobre cuanta información privada quieren compartir con los proveedores de servicio. Utilizamos tecnologías existentes y desarrolladas en esta tesis para proteger a los usuarios de la recolección excesiva de datos por parte de los proveedores de servicio en aplicaciones especfíficas. En particular, utilizamos un nuevo esquema de firma digital basado en la identidad y con umbral dinámico para implementar un sistema de acreditación del tamaño de un grupo, que no desvela ninguna información de los miembros del grupo excepto el número de integrantes, para construir un sistema de descuentos de grupo. A continuación, utilizamos una nueva construcción basada en firmas ciegas, pruebas de conocimiento nulo y técnicas de generalización para implementar un sistema de descuentos de fidelidad que protege la privacidad de los consumidores. Por último, hacemos uso de protocolos de computación multiparte para implementar dos mecanismos de autenticación implícita que no revelan información privada del usuario al proveedor de servicios.This thesis is about the research and development of privacy enhancing techniques to empower consumers of electronic commerce services with the control on how much private information they want to share with the service providers. We make use of known and newly developed technologies to protect users against excessive data collection by service providers in specific applications. Namely, we use a novel identity-based dynamic threshold signature scheme and a novel key management scheme to implement a group size accreditation mechanism, that does not reveal anything about group members but the size of the group, to support group discounts. Next, we use a novel construction based on blind signatures, zero-knowledge proofs and generalization techniques to implement a privacy-preserving loyalty programs construction. Finally, we use multiparty computation protocols to implement implicit authentication mechanisms that do not disclose private information about the users to the service providers

Best Practices and Recommendations for Cybersecurity Service Providers

This chapter outlines some concrete best practices and recommendations for cybersecurity service providers, with a focus on data sharing, data protection and penetration testing. Based on a brief outline of dilemmas that cybersecurity service providers may experience in their daily operations, it discusses data handling policies and practices of cybersecurity vendors along the following five topics: customer data handling; information about breaches; threat intelligence; vulnerability-related information; and data involved when collaborating with peers, CERTs, cybersecurity research groups, etc. There is, furthermore, a discussion of specific issues of penetration testing such as customer recruitment and execution as well as the supervision and governance of penetration testing. The chapter closes with some general recommendations regarding improving the ethical decision-making procedures of private cybersecurity service providers

Ethical and Unethical Hacking

The goal of this chapter is to provide a conceptual analysis of ethical, comprising history, common usage and the attempt to provide a systematic classification that is both compatible with common usage and normatively adequate. Subsequently, the article identifies a tension between common usage and a normativelyadequate nomenclature. ‘Ethical hackers’ are often identified with hackers that abide to a code of ethics privileging business-friendly values. However, there is no guarantee that respecting such values is always compatible with the all-things-considered morally best act. It is recognised, however, that in terms of assessment, it may be quite difficult to determine who is an ethical hacker in the ‘all things considered’ sense, while society may agree more easily on the determination of who is one in the ‘business-friendly’ limited sense. The article concludes by suggesting a pragmatic best-practice approach for characterising ethical hacking, which reaches beyond business-friendly values and helps in the taking of decisions that are respectful of the hackers’ individual ethics in morally debatable, grey zones

The Ethics of Cybersecurity

This open access book provides the first comprehensive collection of papers that provide an integrative view on cybersecurity. It discusses theories, problems and solutions on the relevant ethical issues involved. This work is sorely needed in a world where cybersecurity has become indispensable to protect trust and confidence in the digital infrastructure whilst respecting fundamental values like equality, fairness, freedom, or privacy. The book has a strong practical focus as it includes case studies outlining ethical issues in cybersecurity and presenting guidelines and other measures to tackle those issues. It is thus not only relevant for academics but also for practitioners in cybersecurity such as providers of security software, governmental CERTs or Chief Security Officers in companies