Jekyll2026-04-21T01:54:35+02:00https://jnsiemer.de/feed.xmlPhD Student at King's College London specialising in lattice-based cryptography. 2026-04-03T00:00:00+02:002026-04-03T00:00:00+02:00https://jnsiemer.de/news/laz-goes-liveThe Lattice Assumption Zoo just launched! While the list of catalogued is assumptions is not exhaustive yet, the concept and architecture are stable. This project yields the first community-driven approach to systematically catalogue the landscape of lattice-based assumptions, which has seen rapid growth in the past five years.

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2026-03-10T00:00:00+01:002026-03-10T00:00:00+01:00https://jnsiemer.de/news/scalable-rbe-at-spOur paper Scalable Registration-Based Encryption from Lattices will be published at S&P’26. We present the first concrete post-quantum instantiation of RBE supporting arbitrary identity spaces and a large number of users with a ciphertext size of 7.0 MB, improving on prior work by three orders of magnitude. More context can be found here.

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2026-02-14T00:00:00+01:002026-02-14T00:00:00+01:00https://jnsiemer.de/news/sis-with-hints-at-pkcOur paper on Tight Reductions for SIS-with-Hints Assumptions was accepted at PKC’26 and provides new reductions between ISIS$_f$, GenISIS$_f$, and their interactive versions, SIS and a GenISIS$_f$ instance, and One-More-ISIS and its randomised variant. More context can be found here.

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2026-01-21T00:00:00+01:002026-01-21T00:00:00+01:00https://jnsiemer.de/news/qfall-goes-liveqFALL Goes Live: Our library suite for rapid prototyping of lattice-based cryptography is now available on crates.io. qFALL pursues a unique path by focussing on usability and low-effort high-level implementations to support researchers during the design phase, enabling an incremental optimisation workflow by replacing bottlenecks with more optimised submodules.

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