We propose a method for optimizing the information theoretic secure goodput of a multiple-input multiple-output (MIMO) degraded wiretap channel using inverse precoding. We evaluate the secrecy capacity of this method in terms of secure goodput under various aspects using a standard fading massive MIMO system under the assumption of perfect channel state information (CSI) at the transmitter for the legitimate channel and no CSI at the transmitter for the eavesdropper channel. The precoding scheme optimizes two parameters, the number of compromised streams and the channel advantage of the legitimate receiver. The resulting secure goodput can be specialized to massive MIMO or optical channels with single or multiple eavesdroppers. We include a numerical analysis of the secure goodput for a multi-mode fiber (MMF) optical channel to demonstrate the flexibility of our approach.