Final answer:
The social engineering tactic where an unauthorized individual gains access to restricted areas by following someone with legitimate credentials is known as tailgating. This is a significant security risk as it can lead to identity theft and unauthorized access to sensitive information.
Step-by-step explanation:
The type of social engineering where one person enters a restricted area using another person's access credentials is commonly known as tailgating. Tailgating is a security risk because it allows unauthorized individuals to gain access to secure areas, often without being detected. This breach of security, where someone follows closely behind another person without the necessary authentication to enter a secured space, can lead to significant risks, such as identity theft, data breaches, and unauthorized access to sensitive information. Identity theft, sometimes called "True-name Fraud," involves the wrongful acquisition and use of a person's personal identification, credit, or account information without permission, leading to activities such as draining savings accounts or incurring large debts. Social engineering itself is a strategy used by cybercriminals to manipulate individuals into breaking normal security procedures. In contrast to options like masquerading, refactoring, and shimming, tailgating specifically refers to the breach of physical security perimeters by following someone with legitimate access.