Top secret : a handbook of codes, ciphers, and secret writing
(Book)

Nonsecret codes -- book code -- dictionary code -- Codetalking -- Pig Latin -- Turkish Irish -- Caesar cipher -- St. Cyr slide -- Keyboard cipher -- Morse code -- Semaphore -- Pigpen cipher -- Rosicrucian cipher -- Date shift cipher -- Greek square cipher -- Greek skytale -- Rail fence cipher -- Route transposition cipher -- Codebreaking -- Early concealment techniques -- Null cipher -- Cardano grille -- Word grille -- Space code -- Playing card code -- Dot cipher -- Line cipher -- Zigzag cipher -- Invisible inks.

Star Books

A handbook for the budding cryptographer including codes and ciphers, invisible inks, concealment techniques, spy stories and some history.