Secret Code Book

Substitution Ciphers

John Redden
2 min readJul 18, 2020

The Secret Code Book is a gentle introduction to substitution ciphers where each chapter eases young readers into the concept of rotation ciphers and work their way up to the Vigenère cipher. Along the way, readers will also learn about geometric approaches to secret codes such as the Pigpen cipher as well as a rich history behind the subject. As a bonus, there is a brief description of frequency analysis and how it is used to crack secret codes!

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In addition, this book actively challenges readers with practice missions where answers are listed in the back. Be sure to find the a cut-out rotation template that is provided to make your very own cipher disk! After reading this book, you will have all the basic tools needed to create secret messages.

For those willing to learn.

John Redden

It’s exciting to come across a topic that is so rich, historically important and essential in modern everyday life. The subject of secret codes and ciphers involves creative thinking, and at the same time it stimulates analytical thought and precision. All this while being fun…

After all, who doesn’t like secret messages?

My hope and dream is that by reading this book you are encouraged to explore more codes and ciphers as well as the stories behind the men and women that have worked in this field. To that end, this book is dedicated to those with the curiosity to imagine and learn. — John Redden

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