The word cryptography has a Greek origin: kryptós = hidden; graphhein = writing. It is a coded writing in which only the sender and receiver of the message can interpret it. The need to write sensitive messages is very old, it has been going on for hundreds of years. The ancient Romans already used cryptography to send battle plans without enemy knowledge, as even if the message were intercepted, with the existing encoding, only the Romans could understand it.
Currently, encryption is widely used on the internet. The massive sending of information through the worldwide web of computers requires security regarding the confidentiality of this information. Much of the advancement of cryptography is due to mathematics, which studies and outlines strategies to make encodings more complex and difficult to be interpreted by people who want to have other people's information for misuse (hackers). The security systems of banks, stores and websites use encryption to keep customer and user information confidential. In fiction movies, there are always secret messages sent by spies and agents, all of them using cryptography.
The cryptography used by large companies, governments and banks performs complex calculations to obtain a secure and almost indecipherable model. But you can create a simple template and exchange messages with your friends and colleagues without other people being able to decipher them.
Let's look at a simple example for encoding a message:
Associate a symbol for each letter of the alphabet, as follows:
In this case we use numbers and letters, but you can do it as you see fit. For each letter of the alphabet we establish a “code” (in red in the table). Only you and your friends, with whom you will exchange messages, will be able to know what the encryption code is.
So, imagine that we want to encode the following message: "THE DOG BARKED".
The message, using the encoding above, would look like:6 z9zt6ll6 q9j75.
See that mathematics is present in practically everything around us and a large part of technological development is due to this beautiful science. Use these ideas to deepen your knowledge of mathematics, you will eventually discover a world of great curiosities.
Decipher the following message:9 p9j8p9j7z9 8 x94j9kj7z9
By Marcelo Rigonatto
Mathematical
Kids School Team
