  In this paper, we analyze whether quantum correlations between successive
steps of evaporation can open any way to resolve the black hole information
paradox. Recently a celebrated result in literature shows that `small'
correction to leading order Hawking analysis fails to restore unitarity in
black hole evaporation. We study a toy qubit model of evaporation allowing
small quantum correlations between successive steps and verify the previous
result. Then we generalize the concept of correction to Hawking state by
relaxing the `smallness' condition. Our result generates a nontrivial upper and
lower bound on change in entanglement entropy in the evaporation process. This
gives us a quantitative measure of correction that would mathematically
facilitate restoration of unitarity in black hole evaporation. We then
investigate whether this result is compatible to the established physical
constraints of unitary evolution of a state in a subsystem. We find that the
generalized bound on entanglement entropy leads to significant deviation from
Page curve. This leads us to agree with the recent claim in literature that no
amount of correction in the form of Bell pair states would lead to any
resolution to the information paradox.
