Riverbank Publications No. 19 Formulae for the Solution of Geometrical Transposition Ciphers with original folder. William F. Friedman, Captain Lenox R. Lohr.

Riverbank Publications No. 19 Formulae for the Solution of Geometrical Transposition Ciphers with original folder

Geneva, Illinois: Riverbank Laboratories 1918. First Edition. 24 pages. 22.2 x 28.6 cm. Stiff tan publisher's wraps with cover titles duplicating title page. One of 200 copies per limitation statement on copyright page. Provided in the originally issued Riverbank Laboratories button and string flapped manila envelope with matching limitation number printed in red upper right corner. Clean copy noting several small spots to the publisher's envelope and some creasing. Rusted staples at spine. Near Fine. Wraps. [27999]


A restricted publication not publically available when issued, it appears in a few institutional collections, but is rarely found on the market. '...a highly original attempt to mechanize the solution of transposition ciphers. The basic idea ... was conceived by Lenox R. Lohr, then a captain taking one of the Riverbank courses...While the formulas worked out perfectly and produced innumerable fragments without the cryptanalyst's having tediously to write out innumerable trial transposition rectangles, the geometrical or route transpositions for which they were designed were so rarely used that the work had little practical value. Nevertheless, it was a forerunner of techniques used today with electronic computers.' (Kahn) Authorship attributions from Galland. [ Methods and examples of Deciphering]

See J.S. Galland, An Historical and Analytical Bibliography of Cryptology, page 68 and also Kahn, The CodeBreakers, 1996, p376, Shulman, An Annotated Bibliography of Cryptography, 1976, p80.

Price: $250.00