What is cryptography and explain with example the concept of encryption, decryption, and key? What are system remediation and hardening? Which tool will you use to carry out system remediation and hardening? What are the most system configurations, which you want to fix after installing the server system? What is access control and how you will control the access of users on the Linux server? (Hint: for this, you will use the configuration file.] Why configuration file of any tool which you install on Linux for security purpose is important