Problem
When we want to encrypt any document or message, we must use cryptography, which consists of disarranging the data so that it acquires a random but recoverable appearance. Use the Substitution Cipher technique to encrypt the following information:
A firewall, is a system that protects a computer or a network of computers from intrusions coming from a third network (specifically the Internet). The firewall is a system that allows you to filter the data packets that travel through the network. It is a narrow bridge that filters, at least, the traffic between the internal and external network. A firewall can be a program (software) or a piece of equipment (hardware) that acts as an intermediary between the local network (or the local computer) and one or more external networks.