  Recently there has been a lot of success in using the deterministic approach
to provide approximate characterization of Gaussian network capacity. In this
paper, we take a deterministic view and revisit the problem of wiretap channel
with side information. A precise characterization of the secrecy capacity is
obtained for a linear deterministic model, which naturally suggests a coding
scheme which we show to achieve the secrecy capacity of the degraded Gaussian
model (dubbed as "secret writing on dirty paper") to within half a bit.
