Schulte, StefanStefanSchulte1357687130000-0001-6828-9945Sober, Michael PeterMichael PeterSober2025-01-282025-01-282025Technisch Universität Hamburg (2025)https://tore.tuhh.de/handle/11420/53588Interoperability is crucial for advancing blockchain technology, as many networks operate in isolation. Existing solutions are often inefficient or tailored to specific blockchains. This thesis introduces novel solutions for cross-blockchain communication with oracles utilizing threshold signatures and Zero-Knowledge Succinct Non-interactive Arguments of Knowledge (zk-SNARKs). Additionally, we integrate blockchain technology into Distributed Key Generation (DKG) protocols and present new protocols for cross-blockchain token transfers and smart contract calls, bridging the gaps between different blockchain networks.Interoperabilität ist entscheidend für den Fortschritt von Blockchain-Technologie, da viele Netzwerke isoliert arbeiten. Bestehende Lösungen sind oft ineffizient oder auf spezifische Blockchains zugeschnitten. Diese Arbeit stellt neuartige Lösungen für die Blockchain-übergreifende Kommunikation mit Orakeln unter Verwendung von Schwellenwertsignaturen und Zero-Knowledge Succinct Non-interactive Arguments of Knowledge (zk-SNARKs) vor. Darüber hinaus integrieren wir Blockchain-Technologie in verteilte Schlüsselerzeugungsprotokolle und präsentieren neue Protokolle für blockchain-übergreifende Token-Transfers und Smart-Contract-Aufrufe, um die Lücken zwischen verschiedenen Blockchain-Netzwerken zu schließen.enhttp://rightsstatements.org/vocab/InC/1.0/blockchainblockchain interoperabilitycross-blockchain communicationcross-blockchain smart contract callscross-blockchain asset transfersdistributed key generationComputer Science, Information and General Works::005: Computer Programming, Programs, Data and Security::005.8: Computer SecurityComputer Science, Information and General Works::004: Computer SciencesSocial Sciences::330: EconomicsNatural Sciences and Mathematics::519: Applied Mathematics, ProbabilitiesDoctoral Thesishttps://doi.org/10.15480/882.1450010.15480/882.14500Tai, StefanStefanTaiIn reference to IEEE copyrighted material which is used with permission in this thesis, the IEEE does not endorse any of Hamburg University of Technology’s products or services. Internal or personal use of this material is permitted. If interested in reprinting/republishing IEEE copyrighted material for advertising or promotional purposes or for creating new collective works for resale or redistribution, please go to http://www.ieee.org/publications_standards/publications/rights/rights_link.html to learn how to obtain a License from RightsLink. If applicable, University Microfilms and/or ProQuest Library, or the Archives of Canada may supply single copies of the dissertation.Other