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In cybersecurity the bad guys always win. There are two very rough "proofs of a kind" I use to explain this to students, both well known in military and counte

In cybersecurity the bad guys always win. There are two very rough "proofs of a kind" I use to explain this to students, both well known in military and counter-terrorism analysis. One is called Blotto analysis. As the number of fronts grows large (>12 is an important point) the game favours the attackers. Defenders have to always win on all fronts, but terrorists only have to win once on any of n fronts. Another scenario comes from finite board games like Go. Defenders lose when their back is against a wall. Because the space of practical human security solutions is smaller than the inventiveness of attackers, eventually the attackers win. Biometrics is the poster child for this kind of folly. There are only two edge cases. One is to create proven trustless systems. Such systems cannot involve humans in any way shape or form, and therefore fail by definition as human security solutions. The other is to eliminate all attackers. This does indeed create a fountain of fascinating ethical conundrums with regard to security research and the possibility for strategic limitation of knowledge hazards.

jacquesm 4y ago
Spot on, and given that there seem to be no real guidelines for any of this beyond 'responsible disclosure' the question for me is whether we are accelerating the arms race with all these neat point-and-click tools.
pid-1 4y ago
> Defenders have to always win on all fronts, but terrorists only have to win once on any of n fronts It depends on how you design systems and processes. Let Mn denote the nth defense mechanism of a system. We can build architectures in which the probability of breaches is calculated as: (M0 is pwned) AND (M1 pwned) AND (M2 is pwned) AND (M3 is pwned)..... You can see the total probability can become small quickly, as it's computed as the product of all probabilites. The collorary is: it's possible to design secure systems from insecure building blocks (as long as those are reasonably uncorrelated!) Insecure systems are generally designed the way you suggest in your post: if a single defense mechanism is breached, the whole system will be breached. So you basically are as secure as your weakest link.
- nonrandomstring 4y ago
  Yes, I haven't mentioned defence in depth here. And as you say, serious real world applications are more than a single layer. But of course what we see with DiD is polynomial growth of complexity, so policy, monitoring, rebuild time and so much else gets hard to manage - upshot is someone, somewhere falls back to simpler configurations - and there's the entry point. But sure, thank goodness we've moved beyond a single blacklist firewall these days :)

jacquesm 4y ago

Spot on, and given that there seem to be no real guidelines for any of this beyond 'responsible disclosure' the question for me is whether we are accelerating the arms race with all these neat point-and-click tools.

pid-1 4y ago

> Defenders have to always win on all fronts, but terrorists only have to win once on any of n fronts It depends on how you design systems and processes. Let Mn denote the nth defense mechanism of a system. We can build architectures in which the probability of breaches is calculated as: (M0 is pwned) AND (M1 pwned) AND (M2 is pwned) AND (M3 is pwned)..... You can see the total probability can become small quickly, as it's computed as the product of all probabilites. The collorary is: it's possible to design secure systems from insecure building blocks (as long as those are reasonably uncorrelated!) Insecure systems are generally designed the way you suggest in your post: if a single defense mechanism is breached, the whole system will be breached. So you basically are as secure as your weakest link.

nonrandomstring 4y ago
Yes, I haven't mentioned defence in depth here. And as you say, serious real world applications are more than a single layer. But of course what we see with DiD is polynomial growth of complexity, so policy, monitoring, rebuild time and so much else gets hard to manage - upshot is someone, somewhere falls back to simpler configurations - and there's the entry point. But sure, thank goodness we've moved beyond a single blacklist firewall these days :)