Silver Bullet Metric
Friday, April 24th, 2009No, I don’t believe there is a silver bullet. But, I came up with an interesting thought exercise while I was at RSAcon that I like to call the silver bullet metric. I asked a number of notable security experts, vendors and analysis and everyone had almost the same reaction, which is that this is worth thinking about, but a hugely complex task to complete. So I thought I’d throw it out there and let the community think about it too. Let’s take a theoretical situation where we looked at any single security vendor out there and give them essentially as much money as they needed to do a complete global deployment of one of their security products. So if it was an anti-virus vendor, you’d give them enough to put AV on every desktop. If it were a firewall, it would be at every endpoint, and so on. Now, the metric is a combination of two scores a) how much is the total cost of ownership and b) what percentage of global online fraud has it decreased. Let’s take a few examples.
If you put Anti-virus on every desktop in the world, would you stop viruses from existing? I think any reasonable person who understands how viruses work would say no. It will, however, make the bad guys work harder and iterate faster to get by the filters (boutique malware). So there is actually a diminishing return once you get above a certain level of deployment. On the other hand, at the very lowest end, if only a few people had anti-virus they would be pretty well protected, because the virus authors wouldn’t bother trying to figure out a way around it. Of course everyone else who doesn’t have the AV is screwed in that scenario. So the right percentage of deployment for anti-virus isn’t global, it somewhere in the middle in that simple example.
If we’re talking about firewalls doing proper egress filtering, that would stop some worms from propagating, but it probably wouldn’t solve enough of the problems compared to the other options out there. If we’re talking about whitelisting applications that can run on computers, that would probably solve a much bigger percentage of the problems compared to firewalls, but the total cost of ownership is through the roof - and who is going to monitor and create all those whitelists. Eesh!
But back to AV for a second - AV has the hidden benefit outside of security that theoretically increases longevity of computers. So AV increases the lifetime of the computer, although the decrease in usability of the computer because of the resources that are being used might offset that number. Anyway, all of that factors into the total cost of ownership. Once we go through that exercise (which is probably best left for the product managers of each product line to do) you come up with a few interesting metrics. The first is the silver bullet metric, and the second is exactly what the maximum level of deployment that product or service should get to before it stops being an effective tool for the money - because TCO might change depending on how widely it is deployed as well (economies of scale, diminishing returns, etc…).
I’m not at all saying I have the right answer, or that I do believe there is a single best product out there, but to be the devil’s advocate, what if we did find that one product or service had the best silver bullet metric - what then? Why would we back any other technologies at that point? Anyway, it’s a fun thing to think about. Perhaps it’s just another lens by which to look at the security industry through. Of course this exercise has it’s evil twin too - which is the types of exploits that can be performed and their own associated cost benefit analysis.





