The index of coincidence and its applications in cryptanalysis
Subtitle: technical paper
By: by William F. Friedman.
Contributors: United States. Army. Signal Corps.; George Fabyan Collection (Library of Congress)
Publisher: G.P.O.
Published: 1935
Place of publication: Washington
Language: eng
Number of pages: 87
Subjects: Ciphers.; Cryptography.
Notes: At head of title: War Department, Office of the Chief Signal Officer, Washington.
"Register no. 200."
"The present paper was prepared in 1923. It is a revision of an earlier paper with the same title published in 1922 by the Riverbank Laboratories, Geneva, Ill."-- P. 1.