Abstract
The increase in usage of smartphones and the ubiquity of Internet access have made mobile communications services very attractive to users. Messaging services are among the most popular services on the Internet. In recent years, this services started to support confidentiality and anonymity. A recurrent problem with the existing messaging solutions is their lack of resistance to impersonation attacks. The proposed solution addresses the impersonation problem, without neglecting user confidentiality and anonymity, by forcing users to exchange the required cryptographic material among themselves. Moreover, this exchange must use a proximity communication technology, forcing the users to physically meet.

Abstract
Economical benefits obtained by large Internet corporations from gathering and processing user information at a global scale led the European Union to legislate on behalf of individual rights and the privacy of personal information. Data collectors, in particular, must now obtain proof of the user’s consent for every single operation comprising their data. Considering the conflicting interests of all involved parties, we propose that consent should be stored in a blockchain. By being a distributed, immutable and verifiable ledger, the blockchain presents itself as an almost tailor-made solution to harmonize conflicting interests while enabling the regulators’ supervision. © Springer Nature Switzerland AG 2019.

Abstract
Electronic identity (eID) schemes are key enablers of secure digital services. eIDs have been adopted in several European countries using smart-cards for secure authentication and authorization. Towards achieving a European digital single market where European citizens can seamlessly access cross-border public services using their national eIDs, the European Union (EU) developed the electronic IDentification, Authentication and trust Services (eIDAS) regulation. eIDAS creates an interoperable framework that integrates the eIDs adopted in the EU Member States (MS). It is also an enabler of a cross-border operation, harmonized with the General Data Protection Regulation (GDPR) regulation by protecting the privacy of personal data. If one can use the same procedure for authentication and authorization abroad, one can better understand new services that use eIDs. This paper provides a comparative analysis of eID cards adopted in EU MS and their privacy features in preparedness for eIDs cross-border interoperation. © Springer Nature Switzerland AG 2019.

Abstract
The benefits of blockchain go beyond its applicability in finance. Electronic Voting Systems (EVS) are considered as a way to achieve a more effective act of voting. EVS are expected to be verifiable and tamper resistant. The blockchain partially fulfills this requirements of EVS by being an immutable, verifiable and distributed record of transactions. The adoption of EVS has been hampered mainly by cultural and political issues rather than technological ones. The authors believe that blockchain is the technology that, due to the overall attention it has been receiving, is capable of fostering the adoption of EVS. In the current work we compare blockchain-based EVS, identifying their strengths and shortcomings. © Springer Nature Switzerland AG 2019.

Abstract

Abstract
The digital economy, online presence and the increasing number of phishing attacks, are common realities in today's operations of a significant number of companies. Some of these attacks resulted in significant financial losses and reputational damage. Companies do not address the problem before- hand. The first step should be the assessment of the exposure of the company to phishing attacks. An assessment methodology is proposed, evaluated and tested using two complete, and real, runs of the methodology.