Arvid Gerhard Damm (7 August 1869 – 7 November 1928) was a Swedish engineer and inventor. He designed a number of cipher machines, and was one of the early inventors of the wired rotor principle for machine encipherment. The company, AB Cryptograph, was an early predecessor of Crypto AG. Biography Originally a textile engineer, he was headmaster of a weaving school in Borås, Sweden, before moving to Finland to work as a manager of a textile factory. Although already married with a son, he fell in love with a circus performer from Hungary whose opposition to a relationship he overcame by arranging a sham civil wedding ceremony in 1900 with an officiant and two witnesses. His new “wife”, with whom he then the lived for 19 years, only became aware of the situation when Damm found a new romantic interest and wanted a divorce. After a long and acrimonious legal battle, in which he denied ever being married to her and accused her of being a spy, he was ordered to pay alimony but refused and fled to France. Damm designed a number of crypto machines, based on patents filed in Sweden, the US and many other countries. His most notable invention is that of the rotor principle, laid down in a patent application filed in Sweden on 10 October 1919, three days after Hugo Koch applied for a similar invention in the Netherlands. To exploit his ideas, a company named AB Cryptograph was founded. Originally founded as a patent consortium, Cryptograph was established on 15 June 1915. The company itself began a year later. Cryptograph never became economically viable despite capital infusions by Emanuel Nobel, brother of Alfred Nobel. When Damm’s legal shenanigans in connection with his faked marriage became too much of an embarrassment, he was forced to give up his position in the company and moved to France where he died in 1928. In 1925, Boris Hagelin was placed in charge of the management of the company and the development of its products, having joined AB Cryptograph in 1922. Damm's first machines for Cryptograph were the "Mecano Cryptographer Model A-1" and its interoperable portable counterpart, Model A-2, both produced in 1917. The A-1 was fitted with a keyboard. A later version (1921) could print the plaintext together with two copies of the plaintext onto tape. The machine used a chain of links, which could be reassembled by