Introduction -- Cryptography, cryptanalysis, and cryptology -- The fundamentals of codes, ciphers, and authentication -- Cryptology in private and commercial life -- Cipher systems -- Transposition ciphers -- Substitution ciphers -- Playfair ciphers -- Vigenère ciphers -- Vernam-vigenère ciphers -- Product ciphers -- Key systems and block and stream ciphers -- Single-key cryptography -- Two-key cryptography -- Public-key cryptography -- Secret-sharing -- RSA encryption -- Block and stream ciphers -- Cryptanalysis -- Basic aspects -- Types of cryptanalysis -- Early manual and mechanical cryptography -- The first systems -- World wars I and II -- Modern electronic cryptography -- The impact of electronics -- DES and AES -- Conclusion.