Spyros Kopsidas

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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)
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)
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)
Handling multiple sets of trouble tickets (TTs) originating from different participants in today’s GRID interconnected network environments poses a series of challenges for the involved institutions. Each of the participants follows different procedures for handling trouble incidents in its domain, according to the local technical and linguistic profile.(More)
VoIP and collaboration Internet applications are a driving force for the use and expansion of the Internet. Current applications usually require end user registration in a central user database, which in turn provides directory services to the users of the relevant system; in addition they use either two bridged client- server connections between the end(More)
Voice over IP (VoIP) is one of the most emerging technologies, while a respectable number of corresponding applications are being implemented or updated in daily basis. Although communications security is a constant challenge, most VoIP applications take little or no security provisions. In the present work we describe the design and implementation of a(More)