Frank Miller (1842–1925) was an American cryptographer, banker, and trustee of Stanford University. He invented the one-time pad in 1882, 35 years before the patent issued to Gilbert Vernam. Born in Milwaukee, Wisconsin, in 1842, he graduated from Yale University and then joined the Union Army during the American Civil War, where he was wounded during the Second Battle of Bull Run. References 1842 births 1925 deaths Pre-computer cryptographers Yale University alumni Businesspeople from Milwaukee Union Army soldiers Businesspeople from Sacramento, California