This file was created by the TYPO3 extension bib --- Timezone: CEST Creation date: 2024-04-25 Creation time: 15-53-31 --- Number of references 1 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