We would like to highlight that in
the protocol all other LFSR outputs are masked with random
variables whereas the IDS values use LFSR output sequence
directly. This yields a leakage of the private information.
Adding the variables IDSold from the first session and
IDSold Gn obtained from the next query one can easily
obtain Gn. This provides the adversary to deduce the ID,
hence he will be able trace the tag.