  D0 brane (D-particle) and D1 brane actions possess first and second class
constraints that result in local $\kappa$ symmetry. The $\kappa$ symmetry of
the D-particle and the D1 brane is extended here into a larger symmetry
($\kappa_-$ and $\kappa_+$) in a larger phase space by turning second class
constraints into first class. Different gauge fixings of these symmetries
result in different presentations of these systems while a "unitary" gauge
fixing of the new $ \kappa_+$ symmetry retrieves the original action with
$\kappa_- = \kappa $ symmetry. For D1 brane our extended phase space makes all
constraints into first class in the case of vanishing world sheet electric
field (namely $(0, 1)$ string).
