What technique involves changing the MAC address of an unauthorized device to that of a legitimate one?

The technique that involves changing the MAC address of an unauthorized device to that of a legitimate one is known as impersonation. This method is often used in network attacks where an attacker seeks to gain unauthorized access to a network by adopting the identity of a legitimate device. By altering the MAC address, the unauthorized device can potentially bypass security measures that rely on identifying devices by their MAC addresses. This tactic exploits trust mechanisms within the network, allowing the attacker to appear as a legitimate user or device, thereby gaining access to sensitive data or network resources.

Other techniques mentioned, such as interception and masquerading, involve different methods of exploiting or imitating behaviors within a network. Interception typically refers to eavesdropping or capturing data traffic without the permission of the involved parties, while masquerading generally involves assuming the role of a user without necessarily changing hardware identifiers. Replication might suggest creating copies of devices or data, but it doesn't specifically refer to the act of changing identity through MAC address alteration. Thus, impersonation accurately describes the action of changing a device's MAC address to mimic a legitimate one in network environments.