Cryptography, or cryptology is the practice and study of techniques for secure communication in the presence of third parties. More generally, cryptography is about constructing and analysing protocols that prevent third parties or the public from reading messages.

Prior to the early 20th century, cryptography was mainly concerned with linguistic and lexicographic patterns. Since then the emphasis has shifted. Just as the development of digital computers and electronics helped in cryptanalysis, it made possible much more complex ciphers. Furthermore, computers allowed for the encryption of any kind of data representable in any binary format, unlike classical ciphers which only encrypted written language texts.

This website contains information on the Caesar, Affine and Vigenere cyphers, all are pre 20th century shift cyphers. But enough hopefully to inspire an interest in Cryptography.