One of the fraudulent authentication-based access methods where a person without permission to access a restricted zone intentionally enters said zone together with a person who has access permissions.
Also called 'piggybacking' or 'piggyback,' this is one of the most typical methods of gaining unauthorized access along with a tailgating. Generally, piggybacking refers to the act of gaining unauthorized access with intent, while tailgating refers to the act of gaining unauthorized access without intent.

Piggybacking is a general term referring to the following physical actions and methods of gaining access for malevolent purposes.

• A method through which, after an authorized user has attempted to authenticate themselves and then left the gate, an unauthorized user enters a restricted zone.
• A method through which an authorized user authenticates themselves and then enters the system together with an unauthorized user via 'piggyback.'
• The act of gaining global Internet access by using a wireless network signal from another person.