Mich and the additional authors make some excellent points; however, I would point to defense-in-depth, of course given that it is accomplished correctly, you integrate bi-directional controls from outside in and from inside out. Having implemented security architectures that support this philosophy numerous times, I have seen the successes personally. I will say though that given the sophistication of attacks and the related tools currently used globally, that once again the defense lacks behind the offense. Good stuff......

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