  In this MSc. thesis, we have attempted to give an overview of the firewall
paradox and various approaches towards its resolution. After an introductory
chapter on some basic concepts in quantum field theory in curved spacetimes
such as Hawking radiation, we introduce the paradox. It arises out of
application of principles each of which is thought or assumed to be correct: 1)
unitary black hole evaporation, 2) validity of quantum field theory in curved
spacetime, 3) a measure of the number of black hole quantum states, 4)
Einstein's equivalence principle. Then, we present various approaches that
exist in the literature towards the resolution of the paradox.
