Cryptography and its Apparent Link to Common Sense

Recently I have enrolled in a cryptography class at my local university. It has been very interesting to date and students have been instructed to read a book by Simon Singh called The Code Book. This book exemplifies the importance of cryptography and addresses numerous ways that cryptography has been used in the past to save lives in war, and many other ways, all with the premise of one common but lethal idea, secrecy.

One very interesting point that Singh makes in his book on page 15 is that “Cryptanalysis could not be invented until a civilization had reached a sufficiently sophisticated level of scholarship in several disciplines, including mathematics, statistics, and linguistics.” At first glance this stance on cryptography makes perfect sense, that is until one has tried to decrypt a message with a common cryptanalysis technique himself. It is only then when one realizes that the statement Mr. Singh wrote may not be as true as he thinks.

Before the first lecture of my aforementioned cryptography class, each student was assigned to try and decrypt a message with nothing but only common sense. I do not have the statistics, but I do know that nearly everyone in the class was able to do it. One could argue that the message was only encrypted with a basic cryptanalysis technique, the substitution cypher, so it would be pretty easy to decrypt it, and they would be right. However, Singh does not mention the complexity in his quote listed above. So maybe if we extrapolated my small scale class experiment (which only had a sample size of approximately 30 students), maybe Singh could be proven wrong and a random civilization would be capable of setting up a cryptography technique to use to protect the aspect of secrecy in their civilization.

I believe Singh overthought his quote and the reason why the majority of amateur minds like myself could solve the cryptogram was simply due to common sense and the human mind’s innate ability to find patterns, similarly to how the human mind recognizes facial patterns in people. To me, it is the curiosity of people combined with the natural ability to find patterns that makes cryptography so effective and why people can pick up on it relatively easy.