As Singh noted in the book: " In the latter half of the 19th century, there was an enormous growth of interest in ciphers among the general public." Ciphers are used a lot more frequently in people's daily lives. Several reasons helped raise the popularity of ciphers among the public.
The improvement of technology and educational levels would be one of the main causes. Mathematical methods such as frequency analysis are essential for deciphering or encrypting ciphers. Those methods which were not available in the past began to be recognized and used by the general public, which leads to the flourishing of ciphers in the society.
The wide uses of ciphering are the most important cause of the rising popularity of ciphers. After several incidents happened, people began to understand the need to protect personal messages of a highly sensitive nature. For people with personal or commercial secrets, sending out ciphered text is the best way for their secrets to be kept. For young lovers in Victoria England where public expressing affection was forbidden, the cipher was a great way for them to communicate with each other. For writers wishing to criticize public figures or organizations, encrypted messages can be sent without being noticed but with the same effect of criticizing the newspapers. For example, The Times once carried a notice without knowing that it was meant to criticize its own paper which was described as a mouthpiece of the government. For letter writers wanting to send out letters with a lower cost, it's much cheaper to send out the message via newspaper using pinprick encryption. The ciphering is used in such a wide range that everyone can make their life easier by using the ciphering methods. That explains why there's an enormous growth of interest in ciphering among the public.
Curiosity toward uncertainty is also one reason that people are crazy about enciphering. When I first got into the process of deciphering an encrypted message, the sense of completion came to me every time I found out the true meaning of a letter. This sense was even more significant in the 1950s when message encrypting was not used that often. Encrypting appeared only in the science fictions books or used by the government secret agents in the past. Think about the sense of accomplishment when you decrypted some codes which were used by secret agents. The proud when the message appeared between the lines of seemingly disorder letters. The sense of exploration when people use this cool and mystery way to read and send messages was responsible for the rise in interest in the past and also today. Puzzles and other intellectual questions can be seen anywhere. With the technology and mathematical methods further improved, we can say that interest in ciphers among the general public today is even more significant than that of in the past.