What practice ensures that a computer system is protected against unauthorized access?

Implementing strong password policies is vital for safeguarding a computer system against unauthorized access because passwords serve as the first line of defense. Strong password policies mandate that users create complex and unique passwords that are difficult for malicious actors to guess or crack. These policies can include requirements for a minimum password length, the use of a combination of uppercase and lowercase letters, numbers, and special characters, as well as regular password changes.

Additionally, such policies often recommend against using easily guessable information, such as birthdays or common words. This approach significantly reduces the risk of unauthorized access, as it ensures that even if someone attempts to breach the system, they will likely struggle to gain successful entry without a strong password.

While regularly updating anti-virus software, engaging in data encryption, and conducting daily system backups are all important aspects of maintaining overall cybersecurity, they do not directly relate to the specific practice of preventing unauthorized access through user authentication as effectively as strong password policies do.