What is the term for unauthorized entry by following someone through a secure door?

The term for unauthorized entry by following someone through a secure door is tailgating. This security breach occurs when an unauthorized individual closely follows an authorized person to gain entry into a secure area. Tailgating is a significant concern in physical security because it highlights the importance of access control measures and the need for individuals to ensure that they are not followed into restricted areas.

While both tailgating and piggybacking describe similar behaviors, tailgating specifically refers to the scenario where the unauthorized person does not have permission or authorization, while piggybacking can sometimes imply that the unauthorized individual has the consent of the authorized individual. This distinction is critical in security contexts, making tailgating the more appropriate term to use in this situation.

The concept of impostor access generally suggests an individual explicitly impersonating someone else to gain entry, and hacking is a term more suited to digital security breaches rather than physical access issues.