Terminology

plaintext - ciphertext - cryptanalysis - monoalphabetic - polyalphabetic

Code systems

shift cipher, Vigenere, foursquare, Playfair, transposition


Ancient Languages

Linear B, Hieroglyphics, Demotic, Syllabary, Alphabet, Abjad


Keywords

Polyalphabetic ciphers with keywords. Relevance of repeated words.
Weaknesses of keyword based alphabets (XYZ usually unchanged)


Math

How many different shift ciphers? How many different monoalphabetic ciphers?
Frequency analysis. Bigrams, Trigrams. Use of frequency in foursquare.