  We give conditions that guarantee uniqueness of renormalized solutions for
the Maxwell-Stefan system. The proof is based on an identity for the evolution
of the symmetrized relative entropy. Using the method of doubling the variables
we derive the identity for two renormalized solutions and use information on
the spectrum of the Maxwell-Stefan matrix to estimate the symmetrized relative
entropy and show uniqueness. We then show that weak solutions for the
Maxwell-Stefan system have sufficient regularity to produce renormalized
solutions. Combining the two results yields a uniqueness result for weak
solutions of the Maxwell-Stefan system with bounded fluxes.
