DEVICE AND METHOD FOR PERFORMING AUTHENTICATION IN WIRELESS POWER TRANSFER SYSTEM

A wireless power transmitter including a power converter configured to transfer a wireless power to a wireless power receiver; and a communicator/controller configured to control the wireless power, wherein the wireless power transmitter is configured to transmit, to the wireless power receiver, a bit pattern requesting permission to communicate; receive, from the wireless power receiver, a response packet granting the permission in response to the bit pattern; transmit, to the wireless power receiver, a first auxiliary data transport (ADT) data packet after receiving the response packet; receive, from the wireless power receiver, a not acknowledge (NAK) in response to the first ADT data packet; and transmit, to the wireless power receiver, a second ADT data packet after receiving the NAK, wherein a value of a header for the first ADT data packet is same as a value of a header for the second ADT data packet.