Spyros Kopsidas

Learn More
Secure end-to-end information exchange is a constant challenge in electronic communications. Novel security architectures and approaches are proposed constantly, to be followed by announcements of sophisticated attack methods that compromise them, while people suspect others, even more sophisticated attack methods never see the daylight. In the present work(More)
Pairing devices over insecure wireless channels is a difficult task, especially when there is no trusted third party or when either the delivering network or the third party itself can’t be trusted. In this work we present a light-weight yet sophisticated protocol for establishing secure communications channels between devices. The protocol uses any(More)
Transportation networks are open and accessible, by design, and thus vulnerable to malicious attacks. Transportation networks are integral parts of larger systems, where individual transportation networks form a network-of-networks within a defined geographical region. A security incident on an asset can propagate to new security incidents in interconnected(More)
—The main concern on the use of wireless technologies is security, due to the nature of the medium. User awareness in order to implement efficient security configurations is an important requirement raised by the technology, undermining its use. Wireless Protected Setup (WPS) was introduced as a viable solution to the problem, offering automatic network(More)
Spam is the main problem of email systems nowadays. The total amount of spam emails account for more than 75% of the total emails exchanged worldwide; recent reports raise this number up to more than 90%. Novel anti-spam solutions are proposed constantly, to be followed by announcements of sophisticated methods to overcome them through the use of advanced(More)
In this paper we propose a user based architecture for the email system , where the recipient of an email message manage its receipt in conjunction with both origin and destination email servers. Messages are kept to the origin email server until a confirmation from the recipient is issued though the destination email server. Therefore, spam email doesn't(More)
In this paper we present the architectural design of a secure VoIP conference system for mobile devices, which is using the strong security mechanisms of the Z Real Time Transport Protocol (ZRTP). We also provide implementation fundamentals of the proposed system. We analyze the core elements and we present the primitive characteristics of the component(More)
The present paper introduces a high level modeling language, capable of expressing the concepts and processes of the Strategic Risk Assessment and Contingency Planning in Interconnected Transportation Networks (STAR-TRANS) framework. STAR-TRANS is a comprehensive transportation security risk assessment framework for assessing related risks that provides(More)
Security is a major issue in VoIP communications over the Internet, especially in mobile environments. Voice Interactive Personalized Security (VIPSec) constitutes a method for leveraging the security for Internet communications, with biometric based authentication, exploiting the nature of the application. During the establishment of the communication(More)