Cryptography has been used since ancient times to send hidden messages. The MIS-X, the Enigma Machine, the Vigenere Cipher, and the Spartan Scytale are examples from history. For the average person, cryptography remains behind the scenes. It's intertwined in the everyday tasks that people complete online, on cell phones, and on other devices. But it is always there, thanks to the scholars and codebreakers who worked through the centuries to turn cryptography into what it is today. Developed by Timothy Rasinski and featuring TIME content, this high-interest book includes essential text features like an index, captions, glossary, and table of contents. The intriguing sidebars, detailed images, and in-depth Reader's Guide require students to connect back to the text and encourage multiple readings. The Think Link and Dig Deeper! sections develop students' higher-order thinking skills. The Check It Out! section includes suggested books, videos, and websites for further reading. Aligned with state standards, this title features complex and rigorous content appropriate for students preparing for college and career readiness.