This book starts with the history of security and privacy for laymen and it finishes with a rather mathematical treatment of error-correcting codes. All this is followed by about one hundred pages of mathematical appendices. The first two chapters (altogether about one hundred pages) comprise a brief history of ciphers from the times of Ancient Egypt to the end of World War II. The author describes in detail some important developments, while the description of others (like the breaking of the German Enigma cipher by Polish mathematicians in 1932 and its continuation in the British cryptoanalytical centre in Bletchley Park through World War II) are rather sketchy. Then the author devotes almost three hundred pages to a more detailed description of the modern “computer era” cryptology over the last sixty years. He also touches on various ethical issues of privacy, cyber-crime, etc. The book concludes with a rather technical treatment of Shannon’s theory of information and error-correcting codes. The book has a very broad range aimed at various groups of readers. Anyone interested in the area can probably find something useful to them in it.