What code is hidden on the 3700-year old Phaistos disc?
Why is the Voynich manuscript still unsolved after more than 400 years?
Did the decryption of the Zimmerman telegram help end World War 1?
What system was developed by GCHQ to make cipher exchange more secure and how does it work?
Since we first learned to communicate, the codemaker's craft has challenged and fascinated us. For millennia, mankind has used the transmission of encrypted messages to protect privacy, share secrets, conceal truths and win wars. Highlighting the work of famous cryptanalysts, such as Alan Turing and the Colossus computer, De/Cipher offers compelling insight into the world of cryptography, revealing the cunning and ingenuity behind fifty of the greatest codes and ciphers.
Mark Frary is a writer on science and technology and graduated from University College London with a first class degree in astronomy and physics. He has carried out research into spacecraft at the Mullard Space Science Laboratory in Surrey and nuclear physics on the large electron-positron collider at CERN, the European Laboratory for Particle Physics in Geneva, Switzerland.
His work appears regularly in the London Times and other newspapers and magazines. He is the co-author of Codebreaker: the Secret History of Communications, Future Proof, and the author of Freaky Science and Math in your Pocket.
This is an incredibly disappointing book. The subject matter is fascinating, but the treatment is awful. The text is badly written and edited, with many copyediting errors. There are several references to explanatory diagrams that simply aren't in the book - which is a huge omission for something as technical as explaining how a cipher method works. Without the relevant diagrams it's impossible to work out what the text is describing. There's also at least one case of a diagram description referring to different colours to differentiate parts of the diagram, but the diagram is printed in black and white!
That said, this provides a (brief) overview of many significant historical ciphers and codes, and at least attempts to explain many of them in a way so that you can understand how they work - although because of the editing errors it often fails. I did learn some new things, and some of the cipher method descriptions are useful, mostly the older ones which are inherently easier to explain/understand.
But when the book reached modern encryption techniques, the explanations descended into technical gibberish. Reading the book's attempted explanation of a block cipher leaves one none the wiser as to how the method actually works. The description of quantum cryptography is even worse, using an analogy to polarised light, but completely and utterly getting the physical description of polarisation wrong. It even claims that polarisation is the mechanism that makes some sunglasses go darker in bright light - which is simply wrong.
The only real use for this book might be to find out about a list of historical cipher methods and then going to look them up in a reputable reference to really understand how they work.
My problem with this book is that it advertised teaching you about the greatest codes ever written and how to break them, and it really does neither. It's a broad, general overview of some different types of codes and ciphers that doesn't go too deep into the history of any. Nor does it give very thorough explanations on how to solve codes more difficult than substitution and transposition ciphers. A cool book in theory, but false advertising left a bad taste in my mouth.
I was a little doubtful when I first saw this book. Although it has the intriguing tagline 'The greatest codes ever invented and how to crack them' the combination of a small format hardback and gratuitous illustrations made me suspect it would be a lightweight, minimal content, Janet and John approach to codes and ciphers. Thankfully, in reality Mark Frary manages to pack a remarkable amount of content into De/Cipher's slim form.
Not only do we get some history on and instructions to use a whole range of ciphers, there are engaging little articles on historical codebreakers and useful guidance on techniques to break the simpler ciphers. The broadly historical structure takes the reader through basic alphabetic manipulation, keys, electronic cryptography, one time pads and so on, all the way up to modern public key encryption and a short section on quantum cryptography.
We even get articles on some of the best known unsolved ciphers, such as the Dorabella and the Voynich manuscript. (One of the few parts that is disappointing is the Voynich section, as the author seems heavily influenced by the Bax interpretation and doesn't give any weight to the perfectly reasonable idea that it's a fake, merely saying 'others who have failed to decode the manuscript merely believe it is a hoax.')
You have to have some interest in cryptography to get the most out of this book. Unlike Simon Singh's Code Book, which takes a more narrative approach, this title is a whole collection of different cipher techniques, each as a separate little article. However, if you do have that interest, this is a delightful little book because it adds in so many different cipher techniques. It would be both an ideal introduction to ciphers to a mathematically minded teenager and a good way to expand your knowledge if you're an adult who sees the fun to be had from ciphers, but doesn't know much detail.
While this book does not delve deeply into the specifics of the codes that have been developed down through history, it does give enough information that a lay person can understand them. With perhaps a bit of effort and access to a mathematical dictionary. Secret codes are always popular with young children, think how popular the “magic decoder rings” have been over time. This book is for adults, which is good, because interest in secret codes is something that many people do not grow out of. Each section is short, most deal with a specific form of encryption while others deal with people that made key contributions and others deal with significant historical events, such as the British cracking of the German codes in both World Wars. This is a fun book to read, if you have paid a lot of interest to encryption in your life, then there may not be a lot of new information. As a personal note, years ago when I was at a math conference, I was allowed to type on an actual German Enigma machine. Later, I described the experience as, “I was so excited I was a half-cup of tea from wetting myself.”