13 public-domain matches
Cipher
Mathematical recreations and problems of past and present times
Telegraph code, 1883
The great cryptogram
Letter To W.F. Friedman Concerning The Adfgvx Cipher
Cipher Printer, A.T. And T. Co
Item For Discussion In Brusa Comsec Conference: Cipher Machines
Patent Application - Friedman Cipher Device
The Reliability And Security Of Cipher Machines; Three Pages Of Text From An Unspecified Friedman Lecture On Comint, 1 January 1947
Cryptography
Monograms & ciphers
The Alphabet-Cipher
The Alphabet-Cipher
The Cipher