From ray at unipay.nl Mon Sep 21 21:32:27 2026 From: ray at unipay.nl (R. Hirschfeld) Date: Mon, 21 Sep 2026 21:32:27 +0200 Subject: [crypto] Fwd: Next CWG: September 25th Programme In-Reply-To: References: Message-ID: <0ac5195c81c125f833b87627f84e68af@unipay.nl> -------- Original Message -------- Subject: Next CWG: September 25th Programme Date: 2026-09-21 18:22 From: Secretariaat DM To: "Hermus, Patricia" Dear Crypto Working Group participant, Please find below the agenda for our next meeting. We look forward to seeing you on Friday, September 25th, from 10:45 to 15:45 at Kargadoor, Utrecht. Our apologies for the delay in sending this invitation and agenda. Best regards, 10:45 ?The ABC of Symmetric Primitives over Integer Rings? Berenika Richterov? Designing a secure symmetric-key cipher over a vector space over a field F_{p^n} is well known and understood by the cryptographic community. Even if the attacks are continuously improving, our current understanding regarding the design and security of the majority of the symmetric-key primitives has not fundamentally changed in the last 20 years. How does this picture change when we move to an integer ring Z_{p^n}? Although easy to state, the question is considerably harder to answer. In this talk, we show how existing statistical and algebraic attacks behave for these ciphers and present new attacks that take into account that not all functions over integer rings admit a polynomial representation. Based on this, we discuss possible design strategies, focusing on the security of the ciphers 11:30 ? Coffee Break 11:45 ?MIKE, an isogney-based NIKE? Krijn Reijnders We present MIKE, a post-quantum non-interactive key exchange (NIKE) with public keys of 80 bytes and a key agreement in 7.5 milliseconds in constant time. MIKE is therefore significantly faster and more practical than any other post-quantum NIKE, but also significantly more complex: at its core, it relies on a monoidal action of Hermition modules on superspecial principally polarized abelian varieties. However, stripping away layers of (beautiful) mathematics, we find at its core a somewhat digestible and comprehensible scheme. In this talk, we present MIKE in the reverse order, starting from the very simple core idea, and building up the necessary complexity that we need to understand MIKE at different levels. 12:30 ? Lunch : (Lunch not included) 14:00 ?On the Common Bias of Majorities: Poly-Time Attacks on Low-Weight PRGs? Akin ?nal Pseudorandom Generators (PRGs) based on Threshold-XOR predicates with large locality and high stretches have recently gained traction, since they lend themselves as shallow weak Pseudorandom Functions (PRFs) to fast multiparty computation protocols. In this talk, I will present fast attacks on such PRGs that achieve substantial advantages over the previous attacks of Fu, Li, Lyu and Liu (EC'26). Concretely, they break the security levels of most parameters collected by Boura, Couteau, Perrin and Rotella (ToSC'25), as well as those proposed by Fu, Li, Lyu and Liu (EC'26). On the asymptotic side, we get poly-time attacks with noticeable advantage for Threshold predicates of linear sizes. 14:45 ? Coffee Break 15:00 ?Formal Verification of Assembly Implementations of Cryptographic Functions via Decompilation.? Tom B?n? Implementations of cryptographic primitives need to be both unquestionably secure and highly performant. The second requirement often leads library writers to craft hand-optimized assembly code, which significantly complicates the use of formal methods to satisfy the first requirement. We propose that decompilation techniques can be used to lift cryptographic code written in assembly to Jasmin, a language designed for high-assurance cryptography, and machine-checked for conformance against verified reference implementations, potentially offering comparable guarantees, and evaluate the viability of our approach with case studies drawn from mainstream cryptographic libraries. 15:45 ? End of activities You're receiving this email because some time ago you requested to receive information about the CWG. We are now moving to a TU/e hosted mailing list, and you will receive a notice that you're added to the CWG mailing list. You can then manage your subscription yourself. Note that the membership list is not available to list members and that posting to this mailing list will be restricted to the mailing list operators, Andreas, Tanja, and me. Kind regards, Met vriendelijke groet Patricia Hermus Management Assistant [cid:image001.png at 01DD442E.58017DA0] Discrete Mathematics/ Domain Mathematics Program Management Mathematics Department of Mathematics and Computer Science Eindhoven University of Technology Metaforum, Groene Loper Building 5, Room MF 5.120 E : p.b.hermus at tue.nl T : + 31- (0)40 247 2549 Not in the office on Tuesdays and Fridays