"that effort could have probably been better used to increase the assurance of the system to be protected." Think about that kind of hard. The average person o

"that effort could have probably been better used to increase the assurance of the system to be protected." Think about that kind of hard. The average person or developer would have to know how to block about everything a hacker can think of on their known configuration. Whereas, a hacker or group knowing nothing of their configuration aiming for highest number of compromises will focus on something widely known or used. Even the recent router hacks were devices that sold by the truckload. Even for a targeted scenario, they still gotta get information most of your employees won't even have if it's backend stuff. Much of what runs at my company is terminal, client server, and web apps on non-descript boxes all through VPN's and such. The attackers have to breach the strongest components or convince someone in IT to give them necessary information. How easy that con is varies company to company but there's methods for reducing risk of it, too. Using a different PDF reader, web server, embedded ISA, and so on takes barely any effort or brains. If its own defaults are decent, the switch immediately gives benefit of less, successful attacks with less downtime or restores needed. Even better if behind a guard that hides what things are running by faking an Intel Windows or Linux box. The few that implemented this strategy told me they went years without problems. If any of it gets popular, that benefit might go away. Worse is Better works in our favor for obfuscation, though. The crowds chase the worse things. The attackers stay right behind them. ;) EDIT: "If security by obscurity doesn't take much effort and doesn't interfere with standard security principles (actually it does already when we think about open design/Kerckhoffs's principle , but what I mean is something like complexity increase) it may not harm your security." Yeah, that's basically how I look at it. It shouldn't invalidate the existing mechanisms. It shouldn't take too much effort. Maybe a bit upfront one time for setup with maintenance being rather low. What one is looking for with obfuscations is that they knock out the average attacker's foothold into boxes or networks without using much time for defender. For high-strength attackers, they should be combined with detection mechanisms so they might expose themselves blindly trying attacks.