Riverbank Publications No. 15 : A Method of Reconstructing the Primary Alphabet from a Single One of the Series of Secondary Alphabets

Riverbank, Geneva Ill: Riverbank Laboratories Department of Ciphers, 1954. Reprint. Comb Bound. Near Fine. Reprint. 3-9,[1-blank] pages. 20 x 26.8 cm. Comb binding over printed tan covers. Minor edge fading to cover, clean internally. There were 2 issues of this publication - both are marked 1917 on the front cover. The second issue (as offered here) was published in a comb binding, with different paper stock (we've seen several colors of the comb binding, the copy offered here in orange). Comb Bound. A restricted publication not publically available when issued, it appears in a few institutional collections, but is rarely offered in the market. A note in Friedman's personal files notes: 'This is a photolithographic copy of the original and was produced in a very few copies in 1954.' It is 'Friedman's first writing on cryptology. The primary alphabet is the mixed alphabet used to form a Vigenere-like tableau for alphabetic encipherment; the secondary alphabet is the one recovered by the cryptanalyst.' (Kahn). Authorship attribution from Galland. [ Methods and examples of Deciphering]

See J.S. Galland, An Historical and Analytical Bibliography of Cryptology, page 67. See also Kahn, The CodeBreakers, 1996, p374. Shulman, An Annotated Bibliography of Cryptography, 1976, p80.