Cyberwarfare: Information Operations in a Connected World, 2nd Edition

Where and Why Defense in Depth Fails

Despite multiple layers of protection, defense in depth can fail in a number of scenarios. Much like the castles that come to mind when you diagram defense-in-depth designs, changes in technology, flaws in design, and trusted insiders can all breach or betray even the strongest defenses. But attacks aren’t the only reason that defense in depth can have problems. Some of the biggest problems with defense in depth result from trade-offs it creates simply because of the way it must be implemented.

Recall the three main concepts from the C-I-A triad: confidentiality, integrity, and ­availability. If you think about these three concepts in the context of defense in depth, it quickly becomes obvious that the more ...