In the first chapter, the examples of cryptography Singh selected were confined to the upper echelons of society: nobles, scholars, religious and military leaders. But perhaps more telling is the affluence of cryptanalysts such as Thomas Phelippes, a linguist fluent in five languages and an accomplished code-breaker; knowing five languages is a feat even in the modern world, but acquiring a new language (much less five) prior to readily accessible educational resources is nothing short of extraordinary.
Phelippes' impressive education supports the hypothesis that cryptography and cryptanalysis are areas of study suitable for only those who have a sufficient understanding of an array of scholarly disciplines and the resources necessary to achieve it. This is perhaps more true of today's world, as modern ciphers and cryptographic techniques are far more complex and difficult to crack than simple substitution ciphers and thus require and even more comprehensive education than was necessary centuries ago.
Fortunately, modern society provides us with the ability to attain a level of education sufficient for developing and cracking substitution ciphers by the time we graduate high school; even people who have no formal training in cryptography are capable of employing advanced classical techniques such as frequency analysis to decrypt secret messages. The ubiquity of this approach is a testament to the modern educational system's ability to produce people capable of thinking creatively to solve new problems.
However, this amount of ingenuity entails a notable problem: it essentially renders substitution ciphers (and other ciphers with similar security levels) useless. If an enciphered message can be cracked by the average person (without the aid of a computer) in the matter of hours, a more secure method of encrypting messages is necessary to hide meaning. Although relatively secure encryption usually doesn't present much difficulty thanks to the advent of computing, it makes securely encrypting a message or quickly decrpyting a secure message without a computer nearly impossible; furthermore, with the power of modern computing at their fingertips, cryptanalysis are constantly working to develop faster ways to decrypt information, rendering insecure techniques that were among the best we had discovered just decades earlier. Modern cryptographers are then presented with a unique challenge: creating systems of encryption that allow the intended recipient to receive the message but are strong enough to remain unbreakable for decades to come.