  We present robust and composable device-independent quantum protocols for
oblivious transfer (OT) and bit commitment (BC) using Magic Square devices. We
assume there is no long-term quantum memory, that is, after a finite time
interval, referred to as \textbf{DELAY}, the states stored in the devices
decohere. By robustness, which is a highlight of our protocols, we mean that
the protocols are correct and secure even when devices are slightly off from
their ideal specifications (the \emph{faulty but non-malicious} regime). This
is an important property, since in the real world, devices would certainly have
small manufacturing errors and cannot be expected to be ideal. To the best of
our understanding and knowledge, none of the known DI protocols for OT and BC
in the literature are robust; they can not guarantee correctness in the faulty
but non-malicious regime. Our protocols are sequentially composable and hence,
can be used as building blocks to construct larger protocols, while still
preserving security guarantees.
