Cryptography, the mathematics of secret codes, the project for children --have fun in cryptoclub! Enigma. American Cryptogram Association - Resources. Topics in cryptography. [1.0] Introduction To Codes, Ciphers, & Codebreaking. v2.3.1 / chapter 1 of 13 / 01 nov 12 / greg goebel / public domain * This chapter outlines the basic concepts, elementary terminology, and origins of codes, ciphers, and codebreaking. * The oldest means of sending secret messages is to simply conceal them by one trick or another.
The ancient Greek historian Herodotus wrote that when the Persian Emperor Xerxes moved to attack Greece in 480 BCE, the Greeks were warned by an Greek named Demaratus who was living in exile in Persia. In those days, wooden tablets covered with wax were used for writing. Demaratus wrote a message on the wooden tablet itself and then covered it with wax, allowing the vital information to be smuggled out of the country. The science of sending concealed messages is known as "steganography", Greek for "concealed writing".
Steganography has a long history, leading to inventions such as invisible ink and "microdots", or highly miniaturized microfilm images that could be hidden almost anywhere. Given the plaintext: s o. Codes.