From ray at unipay.nl Mon Mar 16 18:02:53 2026 From: ray at unipay.nl (R. Hirschfeld) Date: Mon, 16 Mar 2026 18:02:53 +0100 Subject: [crypto] Fwd: CWG: 20 March Programme In-Reply-To: References: Message-ID: -------- Original Message -------- Subject: CWG: 20 March Programme Date: 2026-03-16 15:48 From: "Guarise Vieira, Heloise" To: Dear Crypto Working Group participant, Find below the schedule for our next meeting. We will see you this Friday, 20 March from 10:45h to 15:45h, at the Kargadoor, in Utrecht. Best regards, --------------------------- 10:45 Key management in cloud environments Jurjen Bos In this presentation, I'll give you an inside peek of the banking position towards cryptography. I'll explain how the current trend of moving applications to the cloud makes it harder to maintain cryptographic security. Finally, I describe a research project of myself where I try to find a way to get cryptography to the cloud without compromising security. 11:30 ? Coffee Break 11:45h Protoss Protocol for Tight Optimal Symmetric Security Emanuelle di GIandomenico We present Protoss, a new balanced PAKE protocol with optimal communication efficiency. Messages are only 160 bits long, and the computational complexity is lower than all previous approaches. Our protocol is proven secure in the random oracle model and features a security proof in a strong security model with multiple parties and multiple sessions, while allowing for generous attack queries including multiple Test-queries. Moreover, the proof is in the practically relevant single-bit model (that is harder to achieve than the multiple-bit model) and tightly reduces to the Strong Square Diffie-Hellman assumption (SSQRDH). This allows for very efficient, theoretically sound instantiations and tight compositions with symmetric primitives. 12:30h ? Lunch 14:00h Smoothing the degree of regularity for polynomial systems Melvin Seitner The eXtended Linearization (XL) algorithm is an algebraic method for solving systems of polynomials in multiple variables. It achieves this by taking elements of such a system, up to some degree, and transforming them into linear restrictions. Said degree must be high enough that the resulting linear system is overdetermined, and has a major impact on the runtime of the algorithm. However, this degree is a rather coarse parameter. This leads to cases where XL uses excessively overdetermined systems, because the system for one degree lower is only slightly underdetermined. To reduce this coarseness, we propose a generalisation of XL, which allows for intermediate options between the integer values of the degree. 14:45h ? Coffee Break 15:00h How not to do ARIMAX predictions in FHE Stefan van den Berg To prepare for the next pandemic we attempt to replay the previous pandemic. During the replay we want to perform analysis to predict the number of COVID-19 infections. For this prediction we use ARIMAX. However, we don?t want to bundle all the data at a single party in plain text. Therefore, we use FHE to run the analysis. Certain decisions were not ideal, but we did learn from them. 15:45h ? End of activities -- [Image] Heloise Vieira, PhD Discrete Mathematics Cluster, Project Leader RSO, Program expert in Defense, Security, and Resilience +31 (0)402474864 MetaForum, MF 5.120