@unpublished{63107, abstract = {{We construct good GKP (Gottesman-Kitaev-Preskill) codes (in the sense of Conrad, Eisert and Seifert proposed) from standard short integer solution lattices (SIS) as well as from ring SIS and module SIS lattices, R-SIS and M-SIS lattices, respectively. These lattice are crucial for lattice-based cryptography. Our construction yields GKP codes with distance $\sqrt{n/πe}$. This compares favorably with the NTRU-based construction by Conrad et al. that achieves distance $Ω(\sqrt{n/q}),$ with $n\le q^2/0.28$. Unlike their codes, our codes do not have secret keys that can be used to speed-up the decoding. However, we present a simple decoding algorithm that, for many parameter choices, experimentally yields decoding results similar to the ones for NTRU-based codes. Using the R-SIS and M-SIS construction, our simple decoding algorithm runs in nearly linear time. Following Conrad, Eisert and Seifert's work, our construction of GKP codes follows directly from an explicit, randomized construction of symplectic lattices with (up to constants $\approx 1$) minimal distance $(1/σ_{2n})^{1/2n}\approx \sqrt{\frac{n}{πe}}$, where $σ_{2n}$ is the volume of the 2n-dimensional unit ball. Before this result, Buser and Sarnak gave a non-constructive proof for the existence of such symplectic lattices.}}, author = {{Blömer, Johannes and Xiao, Yinzi and Raissi, Zahra and Soltan, Stanislaw}}, booktitle = {{arXiv:2509.10183}}, title = {{{Symplectic Lattices and GKP Codes -- Simple Randomized Constructions from Cryptographic Lattices}}}, year = {{2025}}, } @misc{63407, author = {{Anonymous, A}}, title = {{{Limitations of the Random Oracle Model}}}, year = {{2025}}, } @misc{63408, author = {{Anonymous, A}}, title = {{{Clustering with Rényi Divergence}}}, year = {{2025}}, } @misc{63406, author = {{Anoynmous, A}}, title = {{{BUFF Transform}}}, year = {{2025}}, } @misc{61879, author = {{Anonymous, A.}}, title = {{{Overview on Threshold Signature Schemes and their Applications}}}, year = {{2025}}, } @misc{61878, author = {{Anonymous, A}}, title = {{{Comparison of Time-Lock Puzzle Constructions and Their Security}}}, year = {{2025}}, } @unpublished{63403, abstract = {{Stateful signatures like the NIST standardized signature schemes LMS and XMSS provide an efficient and mature realization of post-quantum secure signature schemes. They are recommended for long-term use cases like e.g. firmware signing. However, stateful signature schemes require to properly manage a so-called state. In stateful signature schemes like LMS and XMSS, signing keys consist of a set of keys of a one-time signature scheme and it has to be guaranteed that each one-time key is used only once. This is done by updating a state in each signature computation, basically recording which one-time keys have already been used. While this is straightforward in centralized systems, in distributed systems like secure enclaves consisting of e.g. multiple hardware security modules (HSMs) with limited communication keeping a distributed state that at any point in time is consistent among all parties involved presents a challenge. This challenge is not addressed by the current standardization processes. In this paper we present a security model for the distributed key management of post-quantum secure stateful signatures like XMSS and LMS. We also present a simple, efficient, and easy to implement protocol proven secure in this security model, i.e. the protocol guarantees at any point in time a consistent state among the parties in a distributed system, like a distributed security enclave. The security model is defined in the universal composabilty (UC) framework by Ran Canetti by providing an ideal functionality for the distributed key management for stateful signatures. Hence our protocol remains secure even if arbitrarily composed with other instances of the same or other protocols, a necessity for the security of distributed key management protocols. Our main application are security enclaves consisting of HSMs, but the model and the protocol can easily be adapted to other scenarios of distributed key management of stateful signature schemes.}}, author = {{Blömer, Johannes and Bröcher, Henrik and Krummel, Volker and Porzenheim, Laurens Alexander}}, keywords = {{distributed state, hash-based signature, stateful hash-based signature, universal composability, secure enclave}}, pages = {{22}}, title = {{{Secure Distributed State Management for Stateful Signatures with a Practical and Universally Composable Protocol}}}, year = {{2025}}, } @misc{47658, author = {{Anonymous, A.}}, title = {{{Private Set Intersection using Third Generation FHE}}}, year = {{2023}}, } @misc{47659, author = {{Anonymous, A.}}, title = {{{Rational Models in Cryptography Applied to Matching}}}, year = {{2023}}, } @misc{40440, author = {{Pilot, Matthias}}, title = {{{Updatable Privacy-Preserving Reputation System based on Blockchain}}}, year = {{2023}}, } @misc{43374, author = {{Schürmann, Patrick}}, title = {{{ A Formal Comparison of Advanced Digital Signature Primitives}}}, year = {{2023}}, } @inproceedings{44855, abstract = {{Market transactions are subject to information asymmetry about the delivered value proposition, causing transaction costs and adverse market effects among buyers and sellers. Information systems research has investigated how review systems can reduce information asymmetry in business-to-consumer markets. However, these systems cannot be readily applied to business-to-business markets, are vulnerable to manipulation, and suffer from conceptual weak spots since they use textual data or star ratings. Building on design science research, we conceptualize a new class of reputation systems based on monetary-based payments as quantitative ratings for each transaction stored on a blockchain. Using cryptography, we show that our system assures content confidentiality so that buyers can share and sell their ratings selectively, establishing a reputation ecosystem. Our prescriptive insights advance the design of reputation systems and offer new paths to understanding the antecedents, dynamics, and consequences to reduce information asymmetry in B2B transactions.}}, author = {{Hemmrich, Simon and Bobolz, Jan and Beverungen, Daniel and Blömer, Johannes}}, booktitle = {{ECIS 2023 Research Papers}}, title = {{{Designing Business Reputation Ecosystems — A Method for Issuing and Trading Monetary Ratings on a Blockchain}}}, year = {{2023}}, } @misc{43375, author = {{Koch, Angelina}}, title = {{{Privacy-Preserving Collection and Evaluation of Log Files}}}, year = {{2023}}, } @inproceedings{35014, author = {{Blömer, Johannes and Bobolz, Jan and Bröcher, Henrik}}, location = {{Taipeh, Taiwan}}, title = {{{On the impossibility of surviving (iterated) deletion of weakly dominated strategies in rational MPC}}}, year = {{2023}}, } @inproceedings{43458, author = {{Blömer, Johannes and Bobolz, Jan and Porzenheim, Laurens Alexander}}, location = {{Guangzhou, China}}, title = {{{A Generic Construction of an Anonymous Reputation System and Instantiations from Lattices}}}, year = {{2023}}, } @misc{32399, author = {{Vahle, Ella}}, title = {{{Modelling and Proving Security for a Secure MPC Protocol for Stable Matching}}}, year = {{2022}}, } @misc{32398, author = {{Siek, Hanna}}, title = {{{Bringing Structure to Structure-Preserving Signatures: Overview, Implementation and Comparison of Selected SPS Schemes}}}, year = {{2022}}, } @misc{31485, author = {{Kramer, Paul}}, title = {{{On Transforming Lattice-Based Cryptography to the Ring Setting}}}, year = {{2022}}, } @misc{34962, author = {{Anonymous, A}}, title = {{{Evaluating database systems relying on secure multiparty computation}}}, year = {{2022}}, } @misc{34963, author = {{Anonymous, A}}, title = {{{Cost of Privacy-preserving SMPC Protocols for NN-Based Inference}}}, year = {{2022}}, }