In the era of rapid technological advancement, the use of cryptography has become an important factor in protecting corporate employees and their customers’ personal information and privacy. Actually, not only the corporates use the cryptography, we can also see the cryptography appears in our daily life.

In Chapter 1 of The Code Book, the author use many examples of well-resourced people such as Mary Queen, the leader of Greece and Persia, and many other types of people who are very important for the country or the security of the country.

In China, there are also these types of the cipher by using in the ancient. “Yin Fu” can be regarded as the earliest military password. When using the two parts, each party will perform half of it to verify the true and the false. The Yin is different in length and length, representing the corresponding intelligence. There is no text on it, even if the enemy seizes it, it cannot be deciphered. In conjunction with the Yin Fu, there is also a “Yinshu“, which is to write a complete piece of information into three pieces and send them separately. After receiving the complete information, the recipients spliced and read the information.

But why should the author use these types of examples? Are there only these people use the cipher in the daily life? The answer is absolutely not. People also use the cipher in their daily life.

In ancient Chinese folk, people used gossip to represent weather, marriage, health, etc. The writing of Chinese words is very complex in ancient. So people use different combinations of gossip represent different pieces of information, there will be countless types of ciphers, but people only need to understand and get the key of the cipher according to the parts they need.

In this example, we can see that not only the well-resourced people use the cipher in their communications, the civilians also use the cipher in their daily life. The reason why most of the well-resourced people’s examples are given is these types of ciphers change the world. In other words, these ciphers have some significant influences. Also we can say they survived those ages.