Μεταπτυχιακές Εργασίες

Μόνιμο URI για αυτήν τη συλλογήhttps://pyxida.aueb.gr/handle/123456789/7

Περιήγηση

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Α Β Γ Δ Ε Ζ Η Θ Ι Κ Λ Μ Ν Ξ Ο Π Ρ Σ Τ Υ Φ Χ Ψ Ω

Τώρα δείχνει 1 - 4 από 4

Comparative analysis and evaluation of authentication frameworks in VANETs
(24-04-2023) Κασιούρης Δημοσθένης; Kasiouris, Dimosthenis; Athens University of Economics and Business, Department of Informatics; Ntouskas, Theodoros; Dritsas, Stylianos
Σε αυτή τη ερευνητική εργασία κάνουμε μία συγκεντρωτική έρευνα και μελέτη δέκα(10) πρωτοκόλλων αυθεντικοποίησης στα δίκτυα VANETs. Παραθέτουμε τις μεθόδους που χρησιμοποιούν για να πετύχουν την αυθεντικοποίηση και να εξασφαλίσουν τις παραμέτρους ασφάλειας που απαιτούνται. Ακολούθως αξιολογούμε συγκριτικά τα πρωτόκολλα για να καταλήξουμε σε κάποιες διαπιστώσεις.
Digital resilience: towards a sophisticated cyber security
(02/27/2019) Siakantaris, George; Athens University of Economics and Business, Department of Informatics; Dritsas, Stylianos
We stand on the blink of a technological revolution that will fundamentally alter the way we live, work, and relate to one another. In its scale, scope, and complexity, the transformation will be unlike anything humankind has experienced before.Digital transformation opens new opportunities every day. It also creates an array of new cyber threats. Digital innovations expand the target area for a cyber-attack, as hackers and other threat actors find new ways to penetrate information networks in order to steal and disrupt. Governments and Organizations have to be aware of the emerging areas of vulnerability, to devise a strong strategy to manage cyber risk and to help create sustainable conditions for continued digitization. Digital resilience has been emerged as a new discipline to help organizations deal with cyber problems that cannot be addressed by traditional cyber security solutions.Digital resilience encompasses both cybersecurity and organizational resilience and it aims to defend against potential cyber-attacks so as to ensure survival following adisruptive event. The scope of this thesis is to analyze the scattered literature on organizational aspects of Digital Resilience which are considered to be Cyber Security and Business Continuity. Finally, the EU Directive on Security of network and information systems is taken into consideration as well.
Privacy & security in vehicular Ad-hoc networks
Μαρκόπουλος, Θεμιστοκλής; Athens University of Economics and Business, Department of Informatics; Dritsas, Stylianos
This research discusses the security issues of the Vehicular Ad-hoc Networks. In recent years, there have been growing interest and research efforts in the area of Vehicular Ad-hoc Networks (VANET) because of the variety of services it can offer. These services fall into the categories of safety applications and non-safety applications. Safety is one of the most important goals of VANET since enhanced safety reduces accidents and therefore can improve traffic conditions and even save lives. Besides safety, other services such as Internet access, weather forecast and geolocation information can enrich travel experience by providing travel comfort, convenience and infotainment. The vehicles in VANET are envisioned to be smart in the following perspectives. First, they should incorporate the basic set of sensors such as front and rear radar that receive extra information from surroundings that the human driver is unable to perceive. Secondly, positioning systems such as the Global Positioning System (GPS) are also found essential for driving assistances. Finally, a smart vehicle should also be equipped with a communication system with potentially multiple interfaces, a central computing system and an Event Recording Device (ERD) whose functioning is similar to the black box of an aircraft. There are also proposals stressing that a smart vehicle should also be equipped with Electronic License Plates to better represent the identity of the vehicle and easy the verification and logging process Safety in VANETs is of special concern because human lives are constantly at stake whereas in traditional networks the major security concerns include confidentiality, integrity and availability none of which involves primarily with life safety. Vital information cannot be neither modified nor deleted by an attacker. Nonetheless, security in VANET also indicates the ability to determine the driver responsibility while maintaining driver privacy. Information about the vehicles and their drivers within must be exchanged securely and more importantly, timely in that the delay of message exchange may cause catastrophic consequences such as collision of vehicles. Besides general networks security issues, unique security challenges rises because of the unique characteristics of VANET such as high mobility, dynamic topology, short connection duration and frequent disconnections. These unique features bring security issues such as trust group formation, position detection and protection as well as certificate management The fundamental security requirements of VANET should include authentication, integrity and nonrepudiation. In some specific scenarios, confidentiality should also be provided against attackers. In addition, user’s privacy such as identity and location history is sensitive information and should be preserved against illegal tracking and user profiling for advertisements. The deployment of a comprehensive security system for VANET is very challenging in practice. A security breach of VANET is often critical and hazardous. VANET can benefit from the existing cryptographic solutions for dealing security attacks or by simple modifications of existing solutions. General cryptographic approaches that apply in VANET include public key schemes to distribute onetime symmetric session keys for message encryption, certificate schemes for authentication and randomizing traffic patterns against traffic analysis. VANET is an emerging research area with promising future as well as great challenges especially in its security.
Ανάλυση ζητημάτων ασφάλειας και ιδιωτικότητας σε Συστήματα Πληρωμών BITCOIN
Τατσέλος, Αθανάσιος; Athens University of Economics and Business, Department of Informatics; Dritsas, Stylianos
Bitcoin is a decentralized payment system and a digital asset that is based on the principle Proof-of-Work. It was invented by Satoshi Nakamoto in 2008 and it was released as an open source software. It relies on peer-to-peer networking and strong cryptography algorithms to maintain its integrity.The Bitcoin system is private, has no middlemen and no traditional financial institutions involved in transactions.In the first chapter it is essential to present the fundamentals of Bitcoin in order to develop a thorough understanding of the basic concepts being presented such as Bitcoin Cryptography primitives, Bitcoin infrastructure and Bitcoin ecosystem.In the second chapter, a short but not so brief analysis of the security requirements of Bitcoin. In other words,the vital components needed to maintain the necessary security controls for effective defense and countermeasures against malicious attackers of the Bitcoin infrastructure.The third chapter, is an elaborate network security analysis of utmost importance in order to facilitate a secure network. Moreover, common security issues and concerns are presented such as the notorious “Double-Spend” attack and many more.The fourth chapter describes the key cryptographic features that Bitcoin uses such as SHA-256, a well-known cryptographic function designed by the National Security Agency, which is used for verifying transactions as well as the calculation of Proof-of-Work or Proof-of-Stake. In addition, ECDSA, short for Elliptic Curve Digital Signature Algorithm, is a process that uses a curve and a finite field in pursuance of data verification and authentication of the signature by third parties while the signer retains the ability to create thesignature.ECDSA is used by Bitcoin to ensure that funds can only be spent by their rightful owners.In the fifth chapter a conclusion analysis is introduced and lastly the sixth chapter presents the viability of Bitcoin Cryptocurrency as well as the necessary steps needed in order for Bitcoin to evolve to its full potential .Furthermore, summaries of previous relevant work show that Bitcoin might not be the perfect solution to all world’s monetary problems but its benefits far outweigh the challenges this cryptocurrency has to overcome.

Περιήγηση

Πλοήγηση Μεταπτυχιακές Εργασίες ανά Επιβλέπων "Dritsas, Stylianos"