  We consider a model for secrecy generation, with three terminals, by means of
public interterminal communication, and examine the problem of characterizing
all the rates at which all three terminals can generate a ``secret key,'' and
-- simultaneously -- two designated terminals can generate a ``private key''
which is effectively concealed from the remaining terminal; both keys are also
concealed from an eavesdropper that observes the public communication. Inner
and outer bounds for the ``secret key--private key capacity region'' are
derived. Under a certain special condition, these bounds coincide to yield the
(exact) secret key--private key capacity region.
