Which of the following terms is used for the process of securing a system or a device on a network infrastructure?

System hardening refers to the deliberate process of configuring and securing a host or network device to minimize vulnerabilities - this includes removing default accounts, disabling unused ports and services, applying security benchmarks such as CIS controls, and enforcing least privilege. It is the standard term used across security frameworks for locking down infrastructure components.

Authentication is the process of verifying the identity of a user or system - it is one component that may be configured during hardening but does not describe the overall process of securing a system.

Cryptography is the science of encoding and protecting information through ciphers and keys - it is a technique used within security, not a term for the broader system-securing process.

Sanitization refers to the secure removal or destruction of data from storage media to prevent recovery - it addresses data disposal, not the configuration and securing of a live system.