Professor of Mathematics

Department of Mathematics and Statistics

Northern Kentucky University

Highland Heights, KY 41099

859-572-6672

FAX: 859-572-6097

E-mail christensen@nku.edu

The following files contain an undated version of the US Navy Elementary Course in Cryptanalysis. These files seem to contain the complete “Elementary Course.”

Introduction and Assignments 1 - 4 which contains: Index, Rules for Students, Mechanical Aids in cipher solution, Assignment 1 (Introduction), Assignment 2 (mechanics of the English language), Assignment 3 (Numerical Cipher Alphabets), and Assignment 4 (Polyalphabetic Substitution).

Assignments 5 - 8 which contains: Assignment 5 (Equivalent Cipher Alphabets), Assignment 6 (Sliding Strips, Cipher Disks, and Square Tables), Assignment 7 (Simple Route Transposition), and Assignment 8 (Anagramming).

Assignments 9 - 12 which contains: Assignment 9 (Grille Transposition Ciphers), Assignment 10 (Polygraphic Substitution), Assignment 11 (Diagonal Digraphic Subsitution), and Assignment 12 (Open Code).

Solutions to Assignments 1 - 12

Appendices which contains: Solutions to Assignments #1 to #12, Training Pamphlet #1 (Reconstruction of Simple Cypher Alphabets), Training Pamphlet #2 (General Principles of Communications Security), and Training Pamphlet #40 (A Numerical Method for the Solution of Double Transposition Ciphers).

Other material:

SRH-212 Elementary Cipher Solution 1930

SRH-213 Office of Operations Bulletins which contains Bulletins about cryptography or cryptanalysis. These are heavily redacted versions of Bulletins 5 (1935), 17 (1936), 18 (1936), 19 (1936), 20 (1936), 21 (1936), 22 (1936), 23 (1937), 65 (1941), and 66 (1941). None of the problems appear; what appears are the introductory pages.

SRH-214 Elementary Course in Cryptanalysis c. 1939 which consists of four assignments. Assignment four was not released.

SRH-216 Elementary Course in Cryptanalysis c. 1940 which contains assignments 1, 2, 3, and 12; Training Pamphlet 12 (“The Use of Wireless Telegraphy in the World War, More Especially from the Naval Strategic Point of View” by N. von Koch); and an appendix “List of Common Naval Text.”

“The Use of Wireless Telegraphy in the World War, More Especially from the Naval Strategic Point of View” by N. von Koch.

SRH 171 Secondary Course in Cryptanalysis

Training Pamphlet 3 was Friedman’s “Elements of Cryptanalysis.”