cryptography

Amy and Dan Cahill continue to hunt for clues while reeling from the knowledge of what happened the night their parents died, and they wonder if the end is near as they try to learn the secret behind Grace Cahill's alternate will.

Amy and Dan are separated while trying to retrieve a clue which is guarded by thousands of soldiers and worry they cannot succeed apart.

Amy and Dan, members of the powerful Cahill family, try to uncover the thirty-nine clues which will reveal the secrets of their lineage and find out what really happened to their parents.

By following the instructions in the coded message, Tim finds his birthday present.

Amy and Dan Cahill face their greatest challenge on their quest to find the thirty-nine clues, but in order to discover the secrets of their lineage they will have to make a choice that could impact the world's future.

Discusses the difference between codes and ciphers, examines common codes and ciphers that have been used during wars, and explains how to create simple ciphers.

An illustrated introduction to cryptography and ciphers that discusses the history of codes, code breaking technology, the Code Talkers, and the ways codes are used during the early twenty-first century.

Amy and Dan are separated while trying to retrieve a clue which is guarded by thousands of soldiers and worry they cannot succeed apart.

Explores the hidden facts, dangerous missions, top agents, and secret hideaways of the Cahill family's desperate hunt for the thirty-nine clues that will lead them to the secret of world domination.

Orphans Amy and Dan Cahill, continuing their worldwide quest to track down the thirty-nine clues that will reveal the secret of the Cahill family's power, follow a link to one of the planet's strongest fighters, and have a run-in with the unreliable Alistair.