Frank Miller (cryptographer)

For other people with the same name, see Frank Miller (disambiguation).

Franklin Miller (January 19, 1842 – February 13, 1925)^[1] was an American cryptographer, banker, and trustee of Stanford University. He invented the one-time pad in 1882,^[2] 35 years before the patent issued to Gilbert Vernam.^[3]

Franklin Miller
Born	(1842-01-19)January 19, 1842 Milwaukee, Wisconsin, United States
Died	February 13, 1925(1925-02-13) (aged 83) Berkeley, California, United States
Nationality	American
Alma mater	Yale University
Known for	Invention of the one-time pad
Spouse	Sarah Ednah Pierce ​ ​ (m. 1867; died 1886)​ Elinor Cecilia Cook ​ (m. 1888)​
Children	7

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.^[3]

Miller's goal with ciphering was to save money by compressing telegraph messages. His telegraph code used code groups of 5-digits representing words and phrases common in commercial telegrams. His cipher added a number with 3 digits to each of the 5-digit groups.^[4] In 1882, Miller published a code-book with corresponding numbers for 14,000 terms and parts of sentences, encouraging users to use so-called shift-numbers (3-digit codes) for extra-encryption in case particularly sensitive information is being transmitted.^[5][6]