CREST Practitioner Security Analyst (CPSA) Practice 2026 - Free CPSA Practice Questions and Study Guide

SSH, or Secure Shell, is a protocol used primarily for secure remote administration and communication between networked devices. It commonly operates on port 22, which is designated for its use by the Internet Assigned Numbers Authority (IANA). Port 22 provides a secure channel over an unsecured network, allowing for encrypted communication and protection against eavesdropping.

Understanding this, it’s important to know that other ports listed in the options are associated with different services. For instance, port 21 is used for FTP (File Transfer Protocol), and port 23 is used for Telnet, both of which are less secure compared to SSH. Port 24 isn’t widely recognized as a standard port for known services. This is why port 22 stands out as the correct answer for SSH, being specifically designated and established for that purpose.