Early Ciphers
Homer’s Iliad — thought to date between the sixth and eighth centuries BC — has exactly one reference to writing. It comes up in the story-within-a-story of Bellerophon, who was sent off by an angry monarch with folded and sealed “tablets on which he [the monarch] had traced a number of devices with a deadly meaning,” tablets that Bellerophon was to give to another king, who was supposed to kill Bellerophon after reading the message. To this day, a message that instructs the recipient to kill the messenger is called a “bellerophontic” message. Is Homer’s wording a fancy way to talk about normal writing — or does it indicate the use of a code or cipher? We don’t know.
The earliest use of a cipher for military purposes involved the fifth century BC Spartans of Greece. They used the device called the scytale, a baton. A strip of paper or leather was wrapped around the baton, and the message was writ- ten straight across the different “columns” of the paper or leather. The recipient of the message would wrap the leather or paper around a baton of the same dimensions and then read the message off the material wound about the baton.
The second century BC Greek historian Polybius devised a ciphering system that has been used for centuries. Polybius put the letters of the alphabet in a 5 x 5 array like a short checkerboard. In Polybius’s system, each letter is described in terms of the column and row in which it appears. Thus, “A” is ciphered as “1-1,” “B” as “1-2,” all the way to “Z” as “5-5.” (In this scheme, “I” and “J” are given the same code.)
Julius Caesar, the first century BC Roman statesman, used at least two ciphering systems during the years when he was a general of the Roman armies. These systems are the Caesar Shift and the Caesar Box Codes (we describe both in Chapter 2, and you can try your hand at them in Chapters 7 and 11). After the fall of the Roman Empire in the West (about 476 AD), we know little of the making of codes and ciphers in the West for many centuries.
However, in other parts of the world, cryptography thrived. The rise of Islamic civilization, from the seventh century AD onward, saw the first books written on cryptanalysis, that is, the organized effort to break codes and ciphers.
In Eastern Asia, the use of idiograms (picture writing) in such languages as Chinese made it impractical to use ciphers (substitutes for letters). However, real codes were sometimes used. For example, in 11th century AD China, one military code was based on the 30 words of a particular poem. Each word corresponded to a brief message, like “need more bows and arrows.” A single word of the poem would be sent as the message from one commander to his superior.
The rebirth of learning during the Renaissance, which continued in the Enlightenment, saw a great increase in the use of codes and ciphers in the Western world. The emergence of the central text of Kabbalah, the Zohar, in about 1300, led many Christian scholars to look into the use of gematria to detect secret meanings in sacred writ. The publication of Agrippa’s Three Books of Occult Philosophy in 1531 did a great deal to spread the use of special alphabets to conceal secret religious writings because Agrippa was the first to publish together in tabular form the magical alphabets called “Celestial,” “Malachim” (Hebrew for “angels”), and the enigmatically named “Passing the River.” These magical alphabets were republished centuries later in Francis Barrett’s popular work, The Magus (1801), through which these alphabets became a permanent part of the landscape of esoteric and magical studies.
But it is the worlds of politics and military actions that have seen an explosion of activity in the area of secret writing over the last 600 years. The destinies of nations have hung on the making and breaking of codes. For example, the attempt by Mary Queen of Scots to take the British throne from Elizabeth I of England in 1585 collapsed when the cipher used by her conspirators, led by Anthony Babington, was broken by Elizabeth’s agents.
As cryptography made and unmade nations in Europe, it did the same in the New World. For example, in the American Revolutionary War, a wide variety of cryptographic techniques (including ciphers, code books, and invisible inks) was used on both sides. The same is true of the use of cryptography during the American War Between the States, or Civil War.
Cryptography and the Great Wars
The earliest use of a cipher for military purposes involved the fifth century BC Spartans of Greece. They used the device called the scytale, a baton. A strip of paper or leather was wrapped around the baton, and the message was writ- ten straight across the different “columns” of the paper or leather. The recipient of the message would wrap the leather or paper around a baton of the same dimensions and then read the message off the material wound about the baton.
The second century BC Greek historian Polybius devised a ciphering system that has been used for centuries. Polybius put the letters of the alphabet in a 5 x 5 array like a short checkerboard. In Polybius’s system, each letter is described in terms of the column and row in which it appears. Thus, “A” is ciphered as “1-1,” “B” as “1-2,” all the way to “Z” as “5-5.” (In this scheme, “I” and “J” are given the same code.)
Julius Caesar, the first century BC Roman statesman, used at least two ciphering systems during the years when he was a general of the Roman armies. These systems are the Caesar Shift and the Caesar Box Codes (we describe both in Chapter 2, and you can try your hand at them in Chapters 7 and 11). After the fall of the Roman Empire in the West (about 476 AD), we know little of the making of codes and ciphers in the West for many centuries.
However, in other parts of the world, cryptography thrived. The rise of Islamic civilization, from the seventh century AD onward, saw the first books written on cryptanalysis, that is, the organized effort to break codes and ciphers.
In Eastern Asia, the use of idiograms (picture writing) in such languages as Chinese made it impractical to use ciphers (substitutes for letters). However, real codes were sometimes used. For example, in 11th century AD China, one military code was based on the 30 words of a particular poem. Each word corresponded to a brief message, like “need more bows and arrows.” A single word of the poem would be sent as the message from one commander to his superior.
The rebirth of learning during the Renaissance, which continued in the Enlightenment, saw a great increase in the use of codes and ciphers in the Western world. The emergence of the central text of Kabbalah, the Zohar, in about 1300, led many Christian scholars to look into the use of gematria to detect secret meanings in sacred writ. The publication of Agrippa’s Three Books of Occult Philosophy in 1531 did a great deal to spread the use of special alphabets to conceal secret religious writings because Agrippa was the first to publish together in tabular form the magical alphabets called “Celestial,” “Malachim” (Hebrew for “angels”), and the enigmatically named “Passing the River.” These magical alphabets were republished centuries later in Francis Barrett’s popular work, The Magus (1801), through which these alphabets became a permanent part of the landscape of esoteric and magical studies.
But it is the worlds of politics and military actions that have seen an explosion of activity in the area of secret writing over the last 600 years. The destinies of nations have hung on the making and breaking of codes. For example, the attempt by Mary Queen of Scots to take the British throne from Elizabeth I of England in 1585 collapsed when the cipher used by her conspirators, led by Anthony Babington, was broken by Elizabeth’s agents.
As cryptography made and unmade nations in Europe, it did the same in the New World. For example, in the American Revolutionary War, a wide variety of cryptographic techniques (including ciphers, code books, and invisible inks) was used on both sides. The same is true of the use of cryptography during the American War Between the States, or Civil War.
Cryptography and the Great Wars