Özgür Kesim

ResearcherCrypto

Cryptographer and external PhD researcher at Freie Universität Berlin who designed and implemented the zero-knowledge age-restriction scheme in GNU Taler, letting merchants enforce minors-protection rules without identifying the buyer. His ESORICS 2022 paper with Christian Grothoff, Florian Dold and Martin Schanzenbach shows how a privacy-preserving payment system can satisfy regulation while keeping payers anonymous. He co-founded the Berlin security firm Code Blau and presents Taler's privacy architecture publicly, most recently at Cedarcrypt 2026.