1) The new reader first sends Gn+1 to the TTP via a secure
channel.
2) The TTP verifies whether the received Gn+1 from the
new reader equals to the one received from the previous
owner, if yes, then the new reader gets authenticated.
Then the TTP sends Kn Gn PIN to the reader
where Kn = F(PIN).
3) The reader forwards the messages received from the TTP
to the tag.