Codes and codebreaking

de Andrew Langley · Publicada por primera vez en 2010

"Codes and codebreaking explains how spies through the ages have sent messages in secret. Clever new codes have constantly been developed, only for even cleverer codebreakers to set about uncovering their secrets. Some of these messages have caused wars, and others have saved lives. And still today, codes are a vital part of the spy's trade."--Back cover.