  It is shown that an existing method to study ideal individual attacks on the
BB84 QKD protocol using error discard can be adapted to reconciliation with
error correction, and that an optimal attack can be explicitly found. Moreover,
this attack fills Luetkenhaus bound, independently of whether error positions
are leaked to Eve, proving that it is tight. In addition, we clarify why the
existence of such optimal attacks is not in contradiction with the established
``old-style'' theory of BB84 individual attacks, as incorrectly suggested
recently in a news feature.
