Efe İzbudak

Papers

Preprints

• Sep 2026
  Monodromic Perverse Sheaves on Shifted Contact Stacks arXiv:2609.18796
• Sep 2026
  Shifted Contact Structures on Exact Symplectic Fibrations (with Mehmet Fırat Arıkan and Kadri İlker Berktav) arXiv:2609.08617
• Jun 2026
  Shifted Symplectic Fibrations and Derived Thurston Theorem (with Mehmet Fırat Arıkan and Kadri İlker Berktav) arXiv:2606.21717, submitted
• Jun 2026
  AKSZ Construction for Shifted Contact Structures (with Kadri İlker Berktav) arXiv:2606.13866
• Jun 2026
  Equivariant Contact Darboux Quotients arXiv:2606.11179
• May 2026
  A Derived Legendrian Category for Shifted Contact Stacks (with Kadri İlker Berktav) arXiv:2605.13792, submitted
• May 2026
  Equivariant Quotients of Derived Symplectic Spaces and Legendrian Intersection Theorem (with Kadri İlker Berktav) arXiv:2605.08394, submitted

In preparation

• Derived Contact Surgery (with Kadri İlker Berktav, Mehmet Fırat Arıkan, and Hena Üçkum)
• Derived Contactomorphisms (with Mehmet Fırat Arıkan and Kadri İlker Berktav)
• Relative shifted contact structures and equivariant derived fibrations (with Mehmet Fırat Arıkan and Kadri İlker Berktav)

Earlier work in cryptography

• Aug 2026
  Sub-Cubic Homomorphic Matrix Multiplication via Self-Dual Normal Bases (with Kübra Kaytancı, Ferruh Özbudak, and Erkay Savaş) IACR ePrint 2026/1592, submitted
• Network Efficient Fully Homomorphic Encryption (with Ali Şah Özcan, Tolun Tosun, and Erkay Savaş) In preparation

Selected talks

• May 2026
  Contractibility in Set_Δ METU (notes)
• Apr 2026
  Basics of Set_Δ, three talks METU (notes)
• Dec 2025
  Constructing Spaces METU (notes)
• Dec 2025
  Moduli Problems and Stacks METU (notes)
• Sep 2024
  All Morphisms Are Equal, But Some Morphisms Are More Equal Than Others DRP Türkiye, Sabanci University (video, report, slides)
• 2024–2025
  Six talks in cryptography, at Sabanci University, METU and online Slides: Sparse Packing for CKKS; Lattice-Based Foundations of Homomorphic Encryption; Fast Multiplication and PLWE-RLWE Equivalence; Cryptanalysis of PLWE Based on Zero-Trace Quadratic Roots; HERMES Ring Packing; Ciphertext-Ciphertext Matrix Multiplication

Education

• 2026–2027
  MSc in Mathematics, Universität Hamburg Thesis: Shifted Contact Structures, supervised by Tobias Dyckerhoff; funded by a DAAD-TEV Master's Scholarship; expected September 2027
• 2022–2026
  BSc in Mathematics, Middle East Technical University GPA 4.00/4.00, ranked first in the university

Research experience

• 2026–
  Higher Structures Group, Middle East Technical University Shifted contact structures on derived stacks, with Kadri İlker Berktav
• 2024–2026
  Cryptography and Information Security Group, Sabanci University Algebraic and approximation-theoretic techniques for homomorphic encryption scheme optimization; client-efficient fully homomorphic encryption
• 2024, 2025
  Program for Undergraduate Research (PURE), Sabanci University Supervised by Erkay Savaş. Implemented CKKS bootstrapping and GPU-accelerated algorithms; supervised undergraduate implementation of TFHE (2024 report, 2025 report)

Blog

• Jul 2026
  The Digital Shackles of Proprietary Bloatware: Why Confluence is an Insult to Our Cryptographic Mission

All posts

Software

I have maintained packages on Gentoo Linux as a proxied maintainer and operate a Tor relay to support global internet freedom. Some of my software:

• confluence-latex-injector: a local-first script to compile LaTeX mathematics and brute-force the ADF JSON directly into Confluence.
• pm: a tiny shell script to manage your passwords securely.
• gp: a tiny shell script to generate strong, secure passwords.
• Gentoo packages I maintain on the ::gentoo repository, such as sc-im and mutt-wizard.
• Other scripts, dotfiles and open-source contributions on GitHub.