Blockchain technologies for leveraging security and privacy

Το σύγχρονο διαδίκτυο έχει εξελιχθεί σε ένα πολύπλοκο οικοσύστημα που περιλαμβάνει ανθρώπους, υπηρεσίες, συσκευές και εφαρμογές που αλληλεπιδρούν ανταλλάσσοντας πληροφορίες, οι οποίες ποικίλουν από μηνύματα ηλεκτρονικού ταχυδρομείου και περιεχόμενο κοινωνικής δικτύωσης έως δεδομένα πληθοπορισμού και βιντεοδιασκέψεις. Σε αυτό το πλαίσιο εμφανίζεται ένα πλήθος από απειλές στην ασφάλεια όπως οι ιοί και το κακόβουλο λογισμικό, ενώ παράλληλα διακυβεύεται η ιδιωτικότητα των χρηστών από απειλές όπως η διαρροή προσωπικών δεδομένων, η εξαγωγή μοτίβων χρήσης κ.ο.κ. Η τάση του Διαδικτύου των Πραγμάτων (IoT) καθιστά το οικοσύστημα του διαδικτύου ακόμη πιο πολύπλοκο, προσθέτοντας ένα ευρύ σύνολο υπηρεσιών, εφαρμογών και συσκευών, πολλές από τις οποίες υποστηρίζονται από νέους ρόλους χρηστών, και οι οποίες έχουν ενσωματωθεί τόσο στην καθημερινή ζωή όσο και στη βιομηχανία. Αυτή η εξέλιξη πολλαπλασιάζει το πλήθος των ευκαιριών που είναι διαθέσιμες για εκμετάλλευση στους επιτιθέμενους, καθώς και τον όγκο και την αξία των δεδομένων, αυξάνοντας έτσι τον συνολικό βαθμό κινδύνου για τους εμπλεκόμενους χρήστες. Στην παρούσα εργασία διερευνούμε το πώς η τεχνολογία blockchain μπορεί να χρησιμοποιηθεί για την επαύξηση της ασφάλειας και της ιδιωτικότητας στο μοντέρνο διαδίκτυο, παρέχοντας το υπόβαθρο για προληπτικά μέτρα, καθώς και διευκολύνοντας τη συλλογή, διασφάλιση και ελεγχόμενη πρόσβαση σε ψηφιακά εγκληματολογικά στοιχεία.The contemporary internet has developed into a complex ecosystem involving humans, services, applications, machines and applications that interact exchanging information, ranging from e-mail messages and social media content to crowdsourcing data and videoconferencing. In this context, a number of security threats such as viruses and malware exist, while additionally the users’ privacy is jeopardized by threats such as personal data leakage, usage pattern monitoring, and so forth. The IoT trend renders the Internet ecosystem even more complex, by adding a rich set of services, applications and machines, many of them backed by new user roles; these elements are weaved into everyday life and industry alike. This increases both the number of opportunities available to threat agents for exploitation and the volume and value of the underlying infrastructure and data, increasing thus the user risk level. In this paper, we explore how the Blockchain technology can be used to leverage security and privacy in the modern Internet, both by providing underpinnings for preventive measures and by facilitating digital forensic evidence collection storage, safeguarding and controlled access

Content enrichment through dynamic annotation

This paper describes a technique for interceding between users and the information that they browse. This facility, that we term 'dynamic annotation', affords a means of editing Web page content 'on-the-fly' between the source Web server and the requesting client. Thereby, we have a generic way of modifying the content displayed to local users by addition, removal or reorganising any information sourced from the World-Wide Web, whether this derives from local or remote pages. For some time, we have been exploring the scope for this device and we believe that it affords many potential worthwhile applications. Here, we describe two varieties of use. The first variety focuses on support for individual users in two contexts (second-language support and second language learning). The second variety of use focuses on support for groups of users. These differing applications have a common goal which is content enrichment of the materials placed before the user. Dynamic annotation provides a potent and flexible means to this end

A Framework For Adaptation In secure Web Services

In the context of service-oriented computing, the introduction of the Quality-of-Service (QoS) aspect leads to the need to adapt the execution of programs to the QoS requirements of the particular execution. This is typically achieved by finding alternate services that are functionally equivalent to the ones originally specified in the program and whose QoS characteristics closely match the requirements, and invoking the alternate services instead of the originally specified ones; the same approach can also be employed for tackling exceptions. The techniques proposed insofar, however, cannot be applied in a secure context, where data are encrypted and signed for the originally intended recipient. In this paper, we introduce a framework for facilitating adaptation in the context of secure SOA

Performance Study of Multilayered Multistage Interconnection Networks under Hotspot Traffic Conditions

The performance of Multistage Interconnection Networks (MINs) under hotspot traffic, where some percentage of the traffic is targeted at single nodes, which are also called hot spots, is of crucial interest. The prioritizing of packets has already been proposed at previous works as alleviation to the tree saturation problem, leading to a scheme that natively supports 2-class priority traffic. In order to prevent hotspot traffic from degrading uniform traffic we expand previous studies by introducing multilayer Switching Elements (SEs) at last stages in an attempt to balance between MIN performance and cost. In this paper the performance evaluation of dual-priority, double-buffered, multilayer MINs under single hotspot setups is presented and analyzed using simulation experiments. The findings of this paper can be used by MIN designers to optimally configure their networks

From the web of data to a world of action

This is the author’s version of a work that was accepted for publication in Web Semantics: Science, Services and Agents on the World Wide Web. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Web Semantics: Science, Services and Agents on the World Wide Web 8.4 (2010): 10.1016/j.websem.2010.04.007This paper takes as its premise that the web is a place of action, not just information, and that the purpose of global data is to serve human needs. The paper presents several component technologies, which together work towards a vision where many small micro-applications can be threaded together using automated assistance to enable a unified and rich interaction. These technologies include data detector technology to enable any text to become a start point of semantic interaction; annotations for web-based services so that they can link data to potential actions; spreading activation over personal ontologies, to allow modelling of context; algorithms for automatically inferring 'typing' of web-form input data based on previous user inputs; and early work on inferring task structures from action traces. Some of these have already been integrated within an experimental web-based (extended) bookmarking tool, Snip!t, and a prototype desktop application On Time, and the paper discusses how the components could be more fully, yet more openly, linked in terms of both architecture and interaction. As well as contributing to the goal of an action and activity-focused web, the work also exposes a number of broader issues, theoretical, practical, social and economic, for the Semantic Web.Parts of this work were supported by the Information Society Technologies (IST) Program of the European Commission as part of the DELOS Network of Excellence on Digital Libraries (Contract G038- 507618). Thanks also to Emanuele Tracanna, Marco Piva, and Raffaele Giuliano for their work on On Time