The security goal in this paper is to detect Case I leaks, that
is inadvertent data leaks over supervised network channels.
In other words, we aim to discover sensitive data appearance in
network traffic over supervised network channels. We assume
that: i) plaintext data in supervised network channels can
be extracted for inspection; ii) the data owner is aware of
legitimate data transfers (Case III); and iii) whenever sensitive
data is found in network traffic, the data owner can decide
whether or not it is a data leak. Network-based security
approaches are ineffective against data leaks caused by malware
or rogue insiders as in Case II, because the intruder may
use strong encryption when transmitting the data, and both the
encryption algorithm and the key could be unknown to the
DLD provider