Alexander Gelfond, Russian mathematician and cryptographer (d. 1968)
Alexander Osipovich Gelfond (Russian: Алекса́ндр О́сипович Ге́льфонд; 24 October 1906 – 7 November 1968) was a Soviet mathematician. Gelfond's theorem, also known as the Gelfond-Schneider theorem is named after him.