Ibn ad-Duraihim, according to Qalqashandi, gave seven…

“Hildegard von Bingen, an 11th-century nun who saw apocalyptic visions and was later canonized, had a cipher alphabet which she claimed came to her…

— David Kahn

“Much of the history of cryptology of this time is a patchwork, a crazy quilt of unrelated items, sprouting, flourishing, withering. Only toward the…

— David Kahn

“His method resembles George Bernard Shaw’s way of using the /f/ sound of GH in “tough,” the /i/ sound of o in “women,” and…

— David Kahn

“The world owes its first instructional text on communications security to the Greeks. It appeared as an entire chapter in one of the earliest…

— David Kahn

“Also of great importance in the discovery of linguistic phenomena that led to cryptanalysis was the development of lexicography.”

— David Kahn

“Another steganographic system was still in use in the 20th century: Aeneas suggested pricking holes in a book or other document above or below…

— David Kahn

“Cryptology was born among the Arabs. They were the first to discover and write down the methods of cryptanalysis. The people that exploded out…

— David Kahn

“The technique was at least moderately well known, for Ibn Khaldūn wrote in The Muqaddimah: “Occasionally, skillful secretaries, though not the first to invent…

— David Kahn

“Cryptology served magical purposes frequently throughout the Middle Ages, and even in the Renaissance was still disguising important parts of alchemical formulas.”

— David Kahn

“The only writer of the Middle Ages to describe cryptography instead of just using it was Roger Bacon, the English monk of startlingly modern…

— David Kahn

“General Joseph O. Mauborgne, who became Chief Signal Officer in October, 1937. Mauborgne had long been interested in cryptology. In 1914, as a young…

— David Kahn

“Analyzing the frequency and contacts of letters is the most universal, most basic of cryptanalytic procedures.”

— David Kahn

“The task of the cryptanalysts consisted primarily of reconstructing the wiring and switches of the coding wheels—a task made more burdensome by the daily…

— David Kahn

“the most famous of all those who had an acquaintance with cryptology in the Middle Ages was an English customs official, amateur astronomer, and…

— David Kahn

“Plaintext a might be represented in a long message by all 26 letters. Conversely, any given ciphertext letter might stand for any one of…

— David Kahn