Monday, March 16, 2009

Making the right call

Cloud computing, or on-premises: which is more secure, and which is the better option for your organization?

It’s a simple yes or no question, and yet it shows just how much further security risk management needs to mature in order to command the stature of marketing or finance in driving company strategy. This isn’t to suggest that security is less important to an organization; it just hasn’t made as much progress formalizing and defending its decision making processes. Financial analysis tools can help in this category, so long as they’re not applied too literally.

For example, the “cloud vs. onsite” decision shares some important similarities with the “lease vs. buy” decisions that finance supports all the time. Finance uses a very simple decision rule to choose between alternatives: accept the decision that maximizes the net present value of the investment. Specifically: what is the sum of all cash flows (i.e. investments, expenses and revenues generated) and what discount rate should be applied to reflect the rate of return that is appropriate for this kind of investment decision?

Often the underlying assumptions and analysis are as important to decision makers as the final recommendation, so transparency is essential.

Given the rate of change in most organizations, security isn’t often asked to weigh in on a single investment choice in isolation. Usually, the decision involves picking the best course among alternatives, so it just needs to be clear, based on a consistent set of evaluation criteria, which alternative is comparatively better. And just as with the “lease vs. buy” scenario, decision makers need to see the analysis as well as the recommendation.

To compare alternatives, objectively, from a security perspective:
* Compare architectures. Which has greater complexity, and why? Higher complexity works against high availability.
* Compare security models: count the number and severity of exposures in each environment to attack.
* Compare control strength, using a common framework such as COBIT or ISO 27001: which environment provides greater defense in depth? What controls must perform effectively in order to ensure the security of systems and critical processes?

So long as both alternatives are assessed with standard, open frameworks the analysis will provide both a recommendation and a basis for evaluating all of the essential underlying assumptions. The intent is not to reduce the inherent variability of threat behavior into a single score that can be applied to both environments, or to conduct an expensive, overly detailed exercise. If there is a significant difference among the alternatives, it will begin to appear with a basic review of high level architectures and security models. If there isn’t much difference, then the decision threshold for security is likely to be met by either environment, and the decision rightly shifts to an evaluation of business benefits.

It only becomes difficult when you’re trading off performance and risk. But there’s a way to deal with that as well …

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