My colleague Jörg Resch blogged today about the ignorance regarding layered security approaches. Yes, there is no absolute security. Security is something which is tightly related to risk. Given that we can't have the perfect security, especially not with people using systems, it's always about the balance between the security-imposed risk and the cost of risk mitigation.

That's a very simple balance: The higher the risks are the more you can and should spend on risk mitigation - as long as risk mitigation is feasible (which is not always the case - a life insurance doesn't help you mitigating the risk of dying...). I thoughtfully used the term "security-imposed risk". It is NOT about security risks, but about the consequences of security-related incidents. Stolen data and their abuse, illegal transactions, customer loss due to a decrease in credibility,... - that's what it is about.

But that doesn't change the fundamental: When thinking about security we have to think about risks. I've blogged about Risk Management before. What we have to understand is that there is not THE information or system which has to be protected. We have different types of systems, information, and transactions which are at different risk. And we have to apply security (technology and organization) according to the risk associated with these different systems, information, and transactions.

There is not THE level of security you need. You need appropriate security for different types of transactions and interaction (and the related systems). Using risk as the main criteria in decisions about security investments helps to optimize what is done in IT security. And focusing on few consistent approaches at different levels (for example few different types of authentication with step-up features and so on, based on a versatile authentication platform; for example a consistent authorization strategy with few consistent levels of management and protection) will be much cheaper than spending too much money for point solutions like many (not all) of the DLP tools out there.

Understanding that different types of interactions and transactions have to be protected differently is the key to succesful IT security concepts. Risk is the core criteria to do that. Interestingly, that is not really new. What governmental and military organizations are doing in "information classification" (having started long before the invention of the computer) is nothing else than using risk as a criteria and definining different levels of protection for different interactions and transactions. Such concepts don't have to be extremly complex. But a differentiated view has to be the guideline for everything which is done in IT security.

To learn more about this and to discuss this with your peers, have a look at our upcoming virtual conferences and our European Identity Conference 2010.