During the class discussion of Singh Chapter 1, we talked about how cryptography and cryptanalysis has developed as societies have advanced. Singh states that “Cryptanalysis could not be invented until a society had reached a sufficiently sophisticated level of scholarship in several disciplines, including mathematics, statistics, and linguistics.” Looking back, many of the ciphers once used to encrypt sensitive political messages now seem dangerously insecure. However, at the time they were unbreakable, or nearly so.

An example of this change in thinking can be seen in the way that many children pass secret messages to their friends. Although they may not know the technical name for it, they are able to understand and use a shift cipher—the sort of cipher once used by rulers and generals—even at a young age. Once they get a bit older, they are able to crack one of these ciphers fairly easily too, as our class saw from the first cryptanalysis worksheet. The reason for this is not that kids today are somehow all being born smarter. The difference is that the “scholarship” once available only to the elite has become much more ingrained in our culture. This seems obvious once you mention it, but in fact it can sometimes be overlooked, and it’s something that should be kept in mind when studying cryptography’s history.