Abstract: Access to restricted services and/or places requires authentication. However, authentication is sometimes performed in: i) noisy conditions, ii) hostile environments and iii) constrained settings. By noisy conditions, we refer to noise in the communication channel that may lead to modification of the transmitted information. By hostile environments we mainly refer to environments where attackers may attempt to impersonate legitimate users, while byconstrained settings we refer to environments that may include communication among wireless devices with limited resources. Authentication is a decision making problem where we need to decide whether or not to accept the credentials of an identity-carrying entity. In the context of cryptographic authentication, we have extensively investigated the family of distance bounding protocols. These can be used as the main countermeasure against relay attacks. We analyse the security of such protocols. These authentication problems will also be briefly connected to the problem of privacy-preservation.

Abstract: Cryptocurrencies have emerged as a powerful new technology for financial transactions in a global scale. In this talk we review the cryptographic aspects and security properties of such systems and we discuss open questions both in terms of their realization as well as in terms of expanding the type of services they can offer. We will cover the basics behind proof of work cryptocurrencies such as bitcoin, as well as proof of stake type of cryptocurrencies and we will review various attacks that can be mounted against such systems. We will also overview the design of protocols that utilize a public ledger of transactions as a resource in order to achieve other cryptographic objectives.

Abstract: With the ever-increasing presence of mobile, embedded and networked devices the application area of cryptography has expanded enormously. From cryptographic computations being carried out on a small number of powerful machines in controlled and secure environments (e.g. banking networks), the landscape has changed toward applications of cryptography being executed on a large variety of computing platforms and in uncontrolled environments. The cryptographic algorithms that protect applications run on embedded, mobile platforms such as smart phones, chip-cards, RFIDs, etc. that may be in the possession and under physical control of a malicious user. We provide an overview of attacks against embedded cryptographic devices. We motivate the need for secure implementations and touch on countermeasures.