United States Cryptographic Patents, 1861-1989

United States Cryptographic Patents, 1861-1989 is a 115-page reference work compiled by Jack Levine. It lists every U.S. patent granted for cryptographic devices and methods across more than a century, from an 1861 telegraph-register patent through patents issued in the late 1980s.

The patents are arranged in two separate sequences: one in chronological order by patent date, and a second alphabetical by inventor. The volume works either as a timeline of cryptographic invention or as a lookup tool for a specific patent holder. A number of entries are illustrated with drawings of the cipher machines and devices described in the patents. This is a second, expanded edition, superseding a shorter 1983 printing that covered patents only through 1981.

Levine was a mathematician at North Carolina State University whose research spanned differential geometry, combinatorics, and tensor analysis. He also had a sustained interest in cryptology, publishing a four-volume study of pattern word lists used in cryptanalysis and contributing regularly to Cryptologia, the journal that issued this volume. His papers, including his cryptographic patent research, are held by the NC State University Libraries.