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    <id>7916</id>
    <completedYear/>
    <publishedYear>2020</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst/>
    <pageLast/>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>masterthesis</type>
    <publisherName/>
    <publisherPlace/>
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    <title language="eng">Using Blockchain for Tamper-Proof Broadcast Protocols</title>
    <abstract language="eng">We present the tamper-resistant broadcast abstraction of the Bitcoin blockchain, and show how it can be used to implement tamper-resistant replicated state machines. The tamper-resistant broadcast abstraction provides functionality to: broadcast, deliver, and verify messages. The tamper-resistant property ensures: 1) the probabilistic protection against byzantine behaviour, and 2) the probabilistic verifiability that no tampering has occurred.&#13;
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In this work, we study various tamper-resistant broadcast protocols for: different environmental models (public/permissioned, bounded/unbounded, byzantine fault tolerant (BFT)/non-BFT, native/non-native); as well as different properties, such as ordering guarantees (FIFO-order, causal-order, total-order), and delivery guarantees (validity, agreement, uniform). This way, we can match the protocol to the required environment model and consistency model of the replicated state machine.&#13;
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We implemented the tamper-resistant broadcast abstraction as a proof of concept. The results show that the implemented tamper-resistant broadcast protocols can compete on throughput and latency with other state-of-the-art broadcast technologies. Use cases, such as a tamper-resistant file system, supply chain tracking, and a timestamp server highlight the expressiveness of the abstraction.&#13;
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In conclusion, the tamper-resistant broadcast protocols provide a powerful interface, with clear semantics and tunable settings, enabling the design of tamper-resistant applications.</abstract>
    <identifier type="urn">urn:nbn:de:0297-zib-79165</identifier>
    <licence>Creative Commons - CC BY - Namensnennung 4.0 International</licence>
    <author>Jonas Spenger</author>
    <submitter>Jonas Spenger</submitter>
    <advisor>Alexander Reinefeld</advisor>
    <advisor>Björn Scheuermann</advisor>
    <collection role="institutes" number="vas">Distributed Algorithms and Supercomputing</collection>
    <collection role="projects" number="BIFOLD">BIFOLD</collection>
    <thesisGrantor>Humboldt-Universität zu Berlin</thesisGrantor>
    <file>https://opus4.kobv.de/opus4-zib/files/7916/2020-Spenger-master-thesis-public.pdf</file>
  </doc>
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