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This article presents Christian ciphers counterparts of the well-known Hebrew atbah cipher used in main languages and scripts of the Christan Orient: in Greek, Coptic, and Syriac, in Late Antiquity and the Middle Ages. The article also describes other alphabetic substitution ciphers used in these languages and highlights numerical rules in their construction.

An early Indian cipher that dates perhaps as early as 4th century A.D. is described. Basically, this cipher maps numerals into consonants; the vowels between the consonants may be used freely.

This article is an exposition of a pencil and paper cipher used by Soviet secret agents working inside the U. S. that successfully defied the government's computer-aided attempt at cryptanalysis for several years.

In 1915 First Lt. Joseph O. Maubourgne, later MG Maugorne and Chief Signal Officer, 1937–1941, presents a simple substitution cipher challenge to the Army Signal School. He proposes a test to determine if his new cryptosystem should replace the Cipher Disk and Playfair Cipher then in use.