This file was created by the TYPO3 extension bib --- Timezone: CEST Creation date: 2024-04-19 Creation time: 08-28-42 --- Number of references 5 incollection 2024_matzutt_blockchain-content 2024 3 7 105 301-336 Augmenting public blockchains with arbitrary, nonfinancial content fuels novel applications that facilitate the interactions between mutually distrusting parties. However, new risks emerge at the same time when illegal content is added. This chapter thus provides a holistic overview of the risks of content insertion as well as proposed countermeasures. We first establish a simple framework for how content is added to the blockchain and subsequently distributed across the blockchain’s underlying peer-to-peer network. We then discuss technical as well as legal implications of this form of content distribution and give a systematic overview of basic methods and high-level services for inserting arbitrary blockchain content. Afterward, we assess to which extent these methods and services have been used in the past on the blockchains of Bitcoin Core, Bitcoin Cash, and Bitcoin SV, respectively. Based on this assessment of the current state of (unwanted) blockchain content, we discuss (a) countermeasures to mitigate its insertion, (b) how pruning blockchains relates to this issue, and (c) how strategically weakening the otherwise desired immutability of a blockchain allows for redacting objectionable content. We conclude this chapter by identifying future research directions in the domain of blockchain content insertion. Blockchain content insertion; Illicit content; Pruning; Redaction Springer Advances in Information Security 10 Blockchains – A Handbook on Fundamentals, Platforms and Applications 978-3-031-32145-0 10.1007/978-3-031-32146-7_10 1 RomanMatzutt MartinHenze DirkMüllmann KlausWehrle article 2021_schomakers_insights Computer Law Review International 2021 2 15 22 1 8-15 Social media, cloud computing, and the Internet of Things connect people around the globe, offering manifold benefits. However, the technological advances and increased user participation generate novel challenges for users' privacy. From the users' perspective, the consequences of data disclosure depend on the perceived sensitivity of that data. But in light of the new technological opportunities to process and combine data, it is questionable whether users can adequately evaluate risks of data disclosures. As mediating authority, data protection laws such as the European General Data Protection Regulation try to protect user data, granting enhanced protection to "special categories" of data. This article assesses the legal, technological, and users' perspectives on information sensitivity and their interplay. Technologically, all data can be referred to as "potentially sensitive." The legal and users' perspective on information sensitivity deviate from this standpoint, as some data types are granted special protection by law but are not perceived as very sensitive by users and vice versa. The key findings here suggest the GDPR adequately protecting users' privacy but for small adjustments. Information Sensitivity, Privacy, European Data Protection Law 1610-7608 10.9785/cri-2021-220103 1 Eva-MariaSchomakers ChantalLidynia DirkMüllmann RomanMatzutt KlausWehrle IndraSpiecker gen. Döhmann MartinaZiefle inproceedings 2019_rut_schomakers_privacy 2021 1 27 857-870 Social media, cloud computing, and the Internet of Things connect people around the globe, offering manifold benefits. However, the technological advances and increased user participation generate novel challenges for users' privacy. From the users' perspective, the consequences of data disclosure depend on the perceived sensitivity of that data. But in light of the new technological opportunities to process and combine data, it is questionable whether users can adequately evaluate risks of data disclosures. As mediating authority, data protection laws such as the European General Data Protection Regulation try to protect user data, granting enhanced protection to "special categories" of data. In this paper, we assess the legal, technological, and users' perspectives on information sensitivity and their interplay. Technologically, all data can be referred to as "potentially sensitive." The legal and users' perspective on information sensitivity deviate from this standpoint, as some data types are granted special protection by law but are not perceived as very sensitive by users and vice versa. Our key findings still suggest the GDPR adequately protecting users' privacy but for small adjustments. Information Sensitivity,Privacy,European Data Protection Law mynedata https://www.comsys.rwth-aachen.de/fileadmin/papers/2021/2021-schomakers-3perspectives.pdf https://dl.gi.de/handle/20.500.12116/34788 https://arxiv.org/abs/1911.06569 Gesellschaft für Informatik

Bonn

INFORMATIK 2020 Karlsruhe, Germany INFORMATIK 2020 2020-09-28 to 2020-10-01 English 10.18420/inf2020_76 1 Eva-MariaSchomakers ChantalLidynia DirkMüllmann RomanMatzutt KlausWehrle IndraSpiecker gen. Döhmann MartinaZiefle inproceedings 2018-matzutt-bitcoin-content 2018 2 26 Blockchains primarily enable credible accounting of digital events, e.g., money transfers in cryptocurrencies. However, beyond this original purpose, blockchains also irrevocably record arbitrary data, ranging from short messages to pictures. This does not come without risk for users as each participant has to locally replicate the complete blockchain, particularly including potentially harmful content. We provide the first systematic analysis of the benefits and threats of arbitrary blockchain content. Our analysis shows that certain content, e.g., illegal pornography, can render the mere possession of a blockchain illegal. Based on these insights, we conduct a thorough quantitative and qualitative analysis of unintended content on Bitcoin's blockchain. Although most data originates from benign extensions to Bitcoin's protocol, our analysis reveals more than 1600 files on the blockchain, over 99% of which are texts or images. Among these files there is clearly objectionable content such as links to child pornography, which is distributed to all Bitcoin participants. With our analysis, we thus highlight the importance for future blockchain designs to address the possibility of unintended data insertion and protect blockchain users accordingly. mynedata https://www.comsys.rwth-aachen.de/fileadmin/papers/2018/2018_matzutt_bitcoin-contents_preproceedings-version.pdf 2018-01-07 Online Springer Proceedings of the 22nd International Conference on Financial Cryptography and Data Security (FC), Nieuwpoort, Curaçao Nieuwpoort, Curaçao Financial Cryptography and Data Security 2018 en 10.1007/978-3-662-58387-6_23 1 RomanMatzutt JensHiller MartinHenze Jan HenrikZiegeldorf DirkMüllmann OliverHohlfeld KlausWehrle inproceedings 2017-matzutt-mynedata 2017 1073-1084 Personal user data is collected and processed at large scale by a handful of big providers of Internet services. This is detrimental to users, who often do not understand the privacy implications of this data collection, as well as to small parties interested in gaining insights from this data pool, e.g., research groups or small and middle-sized enterprises. To remedy this situation, we propose a transparent and user-controlled data market in which users can directly and consensually share their personal data with interested parties for monetary compensation. We define a simple model for such an ecosystem and identify pressing challenges arising within this model with respect to the user and data processor demands, legal obligations, and technological limits. We propose myneData as a conceptual architecture for a trusted online platform to overcome these challenges. Our work provides an initial investigation of the resulting myneData ecosystem as a foundation to subsequently realize our envisioned data market via the myneData platform. Presentation slides are in German Personal User Data, Personal Information Management, Data Protection Laws, Privacy Enhancing Technologies, Platform Design, Profiling mynedata_show https://www.comsys.rwth-aachen.de/fileadmin/papers/2017/2017-matzutt-informatik-mynedata.pdf https://www.comsys.rwth-aachen.de/fileadmin/misc/mynedata/talks/2017-matzutt-informatik-mynedata-presentation.pdf Presentation slides Eibl, Maximilian and Gaedke, Martin Gesellschaft für Informatik, Bonn INFORMATIK 2017 Chemnitz INFORMATIK 2017 2017-09-28 English 978-3-88579-669-5 1617-5468 10.18420/in2017_109 1 RomanMatzutt DirkMüllmann Eva-MariaZeissig ChristianeHorst KaiKasugai SeanLidynia SimonWieninger Jan HenrikZiegeldorf GerhardGudergan IndraSpiecker gen. Döhmann KlausWehrle MartinaZiefle