This file was created by the TYPO3 extension bib --- Timezone: CEST Creation date: 2024-04-27 Creation time: 02-41-06 --- Number of references 3 article 2023_pennekamp_purchase_inquiries ACM Transactions on Internet Technology 2023 11 17 23 4 Dynamic and flexible business relationships are expected to become more important in the future to accommodate specialized change requests or small-batch production. Today, buyers and sellers must disclose sensitive information on products upfront before the actual manufacturing. However, without a trust relation, this situation is precarious for the involved companies as they fear for their competitiveness. Related work overlooks this issue so far: Existing approaches only protect the information of a single party only, hindering dynamic and on-demand business relationships. To account for the corresponding research gap of inadequately privacy-protected information and to deal with companies without an established trust relation, we pursue the direction of innovative privacy-preserving purchase inquiries that seamlessly integrate into today's established supplier management and procurement processes. Utilizing well-established building blocks from private computing, such as private set intersection and homomorphic encryption, we propose two designs with slightly different privacy and performance implications to securely realize purchase inquiries over the Internet. In particular, we allow buyers to consider more potential sellers without sharing sensitive information and relieve sellers of the burden of repeatedly preparing elaborate yet discarded offers. We demonstrate our approaches' scalability using two real-world use cases from the domain of production technology. Overall, we present deployable designs that offer two-way privacy for purchase inquiries and, in turn, fill a gap that currently hinders establishing dynamic and flexible business relationships. In the future, we expect significantly increasing research activity in this overlooked area to address the needs of an evolving production landscape. bootstrapping procurement; secure industrial collaboration; private set intersection; homomorphic encryption; Internet of Production internet-of-production https://www.comsys.rwth-aachen.de/fileadmin/papers/2023/2023-pennekamp-purchase-inquiries.pdf ACM 1533-5399 10.1145/3599968 1 JanPennekamp MarkusDahlmanns FrederikFuhrmann TimoHeutmann AlexanderKreppein DennisGrunert ChristophLange Robert H.Schmitt KlausWehrle inproceedings 2021_pennekamp_bootstrapping 2021 11 15 RWTH-2021-09499 In addition to quality improvements and cost reductions, dynamic and flexible business relationships are expected to become more important in the future to account for specific customer change requests or small-batch production. Today, despite reservation, sensitive information must be shared upfront between buyers and sellers. However, without a trust relation, this situation is precarious for the involved companies as they fear for their competitiveness following information leaks or breaches of their privacy. To address this issue, the concepts of confidential computing and cloud computing come to mind as they promise to offer scalable approaches that preserve the privacy of participating companies. In particular, designs building on confidential computing can help to technically enforce privacy. Moreover, cloud computing constitutes an elegant design choice to scale these novel protocols to industry needs while limiting the setup and management overhead for practitioners. Thus, novel approaches in this area can advance the status quo of bootstrapping new relationships as they provide privacy-preserving alternatives that are suitable for immediate deployment. bootstrapping procurement; business relationships; secure industrial collaboration; privacy; Internet of Production internet-of-production https://www.comsys.rwth-aachen.de/fileadmin/papers/2021/2021-pennekamp-bootstrapping.pdf RWTH Aachen University Blitz Talk at the 2021 Cloud Computing Security Workshop (CCSW '21), co-located with the 28th ACM SIGSAC Conference on Computer and Communications Security (CCS '21), November 15-19, 2021, Seoul, Korea RWTH Aachen University Seoul, Korea November 14, 2021 10.18154/RWTH-2021-09499 JanPennekamp FrederikFuhrmann MarkusDahlmanns TimoHeutmann AlexanderKreppein DennisGrunert ChristophLange Robert H.Schmitt KlausWehrle inproceedings 2019_wagner_dispute_resolution 2019 5 Blockchain systems promise to mediate interactions of mutually distrusting parties without a trusted third party. However, protocols with full smart contract-based security are either limited in functionality or complex, with high costs for secured interactions. This observation leads to the development of protocol-specific schemes to avoid costly dispute resolution in case all participants remain honest. In this paper, we introduce SmartJudge, an extensible generalization of this trend for smart contract-based two-party protocols. SmartJudge relies on a protocol-independent mediator smart contract that moderates two-party interactions and only consults protocol-specific verifier smart contracts in case of a dispute. This way, SmartJudge avoids verification costs in absence of disputes and sustains interaction confidentiality among honest parties. We implement verifier smart contracts for cross-blockchain trades and exchanging digital goods and show that SmartJudge can reduce costs by 46-50% and 22% over current state of the art, respectively. Ethereum,Bitcoin,smart contracts,two-party protocols,dispute resolution,cross-blockchain trades mynedata, impact-digital, rfc https://www.comsys.rwth-aachen.de/fileadmin/papers/2019/2019-wagner-dispute.pdf IEEE IEEE International Conference on Blockchain and Cryptocurrency 2019 (ICBC 2019) Seoul, South Korea IEEE International Conference on Blockchain and Cryptocurrency 2019 English 10.1109/BLOC.2019.8751312 1 EricWagner AchimVölker FrederikFuhrmann RomanMatzutt KlausWehrle