Ivan Cvitić

The Proceedings of the XLIII Symposium on Novel Technologies in Postal and Telecommunications Traffic – PosTel 2025 include the research results in the field of postal and telecommunications traffic completed over the past year. The Symposium is organized by the Department of Postal and Telecommunications Traffic of the Faculty of Transport and Traffic Engineering in Belgrade. The co-organizers are: JP “Pošta Srbije”, “Telekom Srbija” a.d., and the Regulatory Agency for Electronic Communications and Postal Services – RATEL. The event is held under the auspices of the Ministry of Science, Technological Development and Innovation of the Republic of Serbia and the Ministry of Information and Telecommunications of the Republic of Serbia. The Symposium focuses on current research in areas of particular importance for postal and telecommunications traffic in Serbia and the surrounding region. The papers are invited and grouped into three sections: • Management of Processes in Postal and Telecommunications Traffic• Postal Traffic, Networks and Services• Telecommunications Traffic, Networks and Services The section Management of Processes in Postal and Telecommunications Traffic encompasses current research and practical solutions that reflect the deep transformations underway in the modern postal and telecommunications sectors. The papers in this section address key topics such as digitalization, sustainability, inclusivity, technological innovation, and new management models. Special attention is given to the role of public–private partnerships, the application of ESG standards, user protection, development of e-services, and the modernization of operations based on IoT technologies. Through various case studies and analytical approaches, the papers highlight the need for organizational reconfiguration of postal operators, the development of inclusive services, and the improvement of user experience quality. This section provides a comprehensive insight into the challenges and opportunities shaping the future of the postal and telecommunications system, emphasizing the importance of strategic management in the process of digital and green transition. The section Postal Traffic, Networks and Services contains papers that, from scientific and professional perspectives, analyze the postal sector and related current developments. Among other topics, the authors explore strategic directions of postal traffic development and models for applying modern information technologies to optimize. Zbornik radova XLIII Simpozijuma o novim tehnologijama u poštanskom i telekomunikacionom saobraćaju - PosTel 2025, sadrži rezultate istraživanja iz oblasti poštanskog i telekomunikacionog saobraćaja u proteklom jednogodišnjem periodu. Organizator Simpozijuma je Odsek za poštanski i telekomunikacioni saobraćaj Saobraćajnog fakulteta u Beogradu. Suorganizatori su: JP ″Pošta Srbije″, ″Telekom Srbija″ a.d. i Regulatorno telo za elektronske komunikacije i poštanske usluge – RATEL.Pokrovitelji su: Ministarstvo nauke, tehnološkog razvoja i inovacija Republike Srbije i Ministarstvo informisanja i telekomunikacija Republike Srbije.Tematika Simpozijuma vezana je za aktuelna istraživanja u oblastima od posebnog značaja za poštanski i telekomunikacioni saobraćaj, kod nas i u okruženju. Radovi su po pozivu i svrstani su u tri sekcije:* Menadžment procesa u poštanskom i telekomunikacionom saobraćaju,* Poštanski saobraćaj, mreže i servisi,* Telekomunikacioni saobraćaj, mreže i servisi.Sekcija Menadžment poslovnih procesa u poštanskom i telekomunikacionom saobraćaju obuhvata aktuelna istraživanja i praktična rešenja koja odražavaju duboke transformacije u kojima se nalazi savremeni poštanski i telekomunikacioni sektor. Radovi u ovoj sekciji bave se ključnim temama kao što su digitalizacija, održivost, inkluzivnost, tehnološke inovacije i novi modeli upravljanja. Posebna pažnja posvećena je ulozi javnoprivatnih partnerstava, primeni ESG standarda, zaštiti korisnika, razvoju e-usluga i modernizaciji operacija zasnovanih na IoT tehnologijama. Kroz različite studije slučaja i analitičke pristupe, radovi ističu potrebu za organizacionom rekonfiguracijom poštanskih operatora, razvojem inkluzivnih servisa i unapređenjem kvaliteta korisničkog iskustva. Ova sekcija pruža sveobuhvatan uvid u izazove i mogućnosti koje oblikuju budućnost poštanskog i telekomunikacionog sistema, naglašavajući važnost strateškog menadžmenta u procesu digitalne i zelene transformacije.Sekcija Poštanski saobraćaj, mreže i servisi sadrži radove koji sa naučnog i stručnog aspekta analiziraju poštanski sektor i pripadajuće aktuelnosti. Autori radova, između ostalog, istražuju strateške pravce razvoja poštanskog saobraćaja, zatim modele primene savremenih informacionih tehnologija za optimizaciju kako tehnološkog procesa, tako iVI regulative. Teme od interesa odnose se na održivost poslovanja poštanskih operatora, sa posebnim akcentom na unapređenje dostave. Kvalitet univerzalne poštanske usluge i proces standardizacije u poštanskom saobraćaju su neki od ključnih izazova. Takođe, predmet interesovanja u ovoj sekciji je primena savremenih tehnoloških rešenja u poštanskoj logistici. Pored toga, autori predlažu primenu odgovarajućih metoda višekriterijumske analize za rangiranje sistema za preradu paketskih pošiljaka.Radovi u sekciji Telekomunikacioni saobraćaj, mreže i servisi posvećeni su aktuelnim dostignućima u razvoju...

Quantum Key Distribution (QKD) networks enable unconditionally secure key exchange using quantum mechanical principles. However, routing cryptographic keys across multi-hop quantum networks introduces challenges unique to quantum communication. This survey analyzes and classifies 26 routing strategies proposed between 2013 and 2024 for terrestrial, satellite, and hybrid QKD infrastructures. Dynamic, key-aware routing algorithms have been shown to reduce service rejection rates by 25-40% compared to static shortest-path methods by incorporating real-time key pool availability and link error rates. Multi-path strategies improve resilience against trusted-node compromise by distributing keys across disjoint routes, albeit with an increase in key consumption of 30-60%. SDN-based orchestration frameworks emerge as essential enablers of flexible, QoS-aware routing for hybrid networks integrating terrestrial fibers and intermittent satellite links. Critical research directions include reducing dependence on trusted nodes through quantum repeaters or post-quantum cryptography, developing standardized key management interfaces for interoperability, and adopting AI-driven predictive routing for adapting to fluctuating network states. This comprehensive synthesis of routing algorithms, performance trade-offs, and unresolved issues offers practical guidance for engineering secure, adaptable, and large-scale QKD networks capable of meeting real-world deployment demands.

This research explores the growing threat of advanced persistent threats (APTs), which pose significant risks to national security, organisational operations and critical infrastructure. APTs have become increasingly sophisticated, targeting various sectors and demanding more effective defences to protect sensitive data and key systems. The focus of this paper is on addressing the rising frequency and complexity of APT attacks, aiming to provide a detailed analysis of their evolving tactics and the need for proactive security measures. Specifically, the paper examines current gaps in APT detection, from the initial stages of infiltration through to the complete removal of the threat. To address these challenges, the study introduces several detection strategies, including advanced correlation techniques, behavioural analysis of network traffic and user activity, and the application of machine learning and AI to improve threat identification. The paper analyses real-world APT incidents and discusses how monitoring and deception tactics can enhance security measures. It highlights the ongoing challenges presented by APTs, particularly their adaptive and dynamic attack methods, and emphasises the need for continuous improvement in defensive strategies. In conclusion, the paper outlines key areas for future research and stresses the importance of a proactive, evolving approach to counter the persistent and evolving nature of APTs.