Ingress, Egress and Data Loss Prevention (DLP)
Although often overlooked, there are two types of attack vectors: ingress and egress (also known as data exfiltration).
Ingress refers to network communications coming in, while egress refers to network communications going out.
While most attack analysis concentrates on the ingress or intrusion into systems, if the adversary’s goal is theft of
information or data, then it is important to consider the vector or path used to remove the data from the owner’s
systems and networks. Data loss prevention software is helpful in this regard. A successful data loss prevention
program helps an organization protect its information and prevent the exfiltration of sensitive data.
Strong DLP solutions cover three primary states of information. Data at rest refers to stored data. DLP solutions
must be able to log where various file types are stored. Crawler applications then explore the information on these
files searching for sensitive data like social security or credit card information. These crawlers determine whether the
storage location follows predefined rules.
Data in motion refers to data traveling through the network. Deep packet inspection (DPI) is used to analyze the
data for sensitive content. DLP solutions can alert management and even block, quarantine or encrypt controlled
information based on controls.
Finally, good DLP solutions manage data in use, which is data movement at the user workstation level. This includes
sending information to printers, thumb drives or even the copy-and-paste clipboard. DLP solutions use agent software
to set rules for data use. All three information types, data in use, data in motion and data in use, must be addressed to
create a full DLP solution.