Mysterious Messages

December 1, 2009
Gr 5-8-Many books present readers with codes to crack and puzzles to solve, but this excellent narrative history of cryptography explains who developed the different systems of encryption and whyand who managed to crack the codes. Blackwood offers an accessible and often funny lesson in alternative history that features many names that readers will know (Julius Caesar, Queen Elizabeth I, and Thomas Jefferson, to name a few), as well as those who worked behind the scenes to create what they hoped were unbreakable ciphers. Wherever matters of national security were at stake, cryptography played a major role, and perhaps the most interesting lesson is that many landmark events would have turned out differently had it not been for cryptographers working on both sides to create and break the other side's secret messages. Blackwood provides challenging examples of each type of cipher for readers to try. The book's clever and appealing format, designed to look like a secret notebook of torn pages, photographs, and sketches taped to the pages, complements the subject perfectly. This is an excellent accompaniment to fiction series like Nancy Springer's "Enola Holmes" books (Philomel), which make use of many of the codes and ciphers Blackwood mentions."Rebecca Donnelly, Loma Colorado Public Library, Rio Rancho, NM"

Copyright 2009 School Library Journal, LLC Used with permission.

October 15, 2009
Grades 5-8 This well-written history of cryptography begins with a pottery-glaze formula encrypted in cuneiform on a clay tablet (1500 BCE) and traces the uses of secret messages in statecraft, espionage, warfare, crime, literature, and business up to the present. Along the way, Blackwood, whose historical novels include Second Sight (2005) and The Shakespeare Stealer (2007), discusses the historical development of coding and encryption and tells many good stories of messages ciphered and deciphered, particularly in English and American history. For readers motivated to understand the codes and ciphers mentioned in the text, he stops to explain their principles and how to use them. The many sidebars and illustrations, including photos, reproductions of artworks and artifacts, and the pictures demonstrating the codes themselves, contribute to the books approachable look. Source notes for quotes, a bibliography, a glossary, and lists of recommended fiction, nonfiction, and Internet sites are appended. A solid introduction to a topic of perennial interest.(Reprinted with permission of Booklist, copyright 2009, American Library Association.)