Data Loss Prevention products (DLP) are designed to help organizations keep tabs on and protect sensitive data that, if lost, could create legal liability, loss of profit, safety or security risks, and so on.
In other words DLP exists to keep sensitive data from falling into the wrong hands.
Some consider the primary task to help guide users in the proper handling of sensitive data, some consider it a compliance checkbox, and others believe it should prevent an insider from intentionally harming the company by leaking data.
A Network World article, "The dark side of DLP" discusses some of the ethical questions of monitoring digital employee actions. These different philosophies warrant slightly different approaches, but all share the need to identify data that shouldn't be leaked, and plug the leak.
However, one thing is for sure – a determined attacker will always find some way to violate these safeguards. Filter Web traffic and the attacker can use steganography. Isolate the system from the Internet and the attacker can plug in a thumb drive, disable USB and reboot into a live OS. Disable booting and glue the USB ports shut and the attacker can use a cell phone camera to snap a picture of that sensitive document. Disallow cameras and the attacker can copy it down by hand... see where this is going?
At some point, all technical controls will fail, and it's up to the users' training, the awareness of their managers, and other non-technical methods to protect the organization. Smart DLP vendors then will not only focus on plugging the leaks, but will provide secure and convenient ways for users to do their jobs and guidance to reinforce all those non-technical controls.
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