  We derive complementarity relations for arbitrary quantum states of
multiparty systems, of arbitrary number of parties and dimensions, between the
purity of a part of the system and several correlation quantities, including
entanglement and other quantum correlations as well as classical and total
correlations, of that part with the remainder of the system. We subsequently
use such a complementarity relation, between purity and quantum mutual
information in the tripartite scenario, to provide a bound on the secret key
rate for individual attacks on a quantum key distribution protocol.
