  We study the Gaussian multiple-input multiple-output (MIMO) wiretap channel,
which consists of a transmitter, a legitimate user, and an eavesdropper. In
this channel, the transmitter sends a common message to both the legitimate
user and the eavesdropper. In addition to this common message, the legitimate
user receives a private message, which is desired to be kept hidden as much as
possible from the eavesdropper. We obtain the entire capacity-equivocation
region of the Gaussian MIMO wiretap channel. This region contains all
achievable common message, private message, and private message's equivocation
(secrecy) rates. In particular, we show the sufficiency of jointly Gaussian
auxiliary random variables and channel input to evaluate the existing
single-letter description of the capacity-equivocation region due to
Csiszar-Korner.
