Enough fluff, smoke, and flash: get to the point.
Why have security?
At the end of the day, it is all about loss. If you don't like experiencing loss then you must do something to avoid, minimize, or control it. Welcome to the world of Security.
Let's first get something out of the way. If you are seeking to eliminate all loss, I admire you enthusiasm, but you are out of your mind. Totally eliminating loss would be wildly expensive and in most cases impossible. How much would it cost to eliminate all auto theft in the world? Much more than is feasible, as just about any solution you propose would have some weakness and require additional measures, which in total would exponentially increase the cost as you near 100% effectiveness. It would become more cost effective to find a better replacement for cars, and destroy them all, rather than prevent all future thefts. Optimal security is not about 100% protection, rather a balance of spending, prevention, and acceptable losses.
The Profile of Loss
Back to reality. Security is about preventing loss and some would argue managing loss or the risk-of-loss. Well, it is splitting hairs, but I would agree with both as they are one in the same. When we talk about loss it encompasses all the tangible costs and impacts as well as the intangibles of missed opportunities, reputation, and goodwill. Only a few types of loss can easily be measured and most cannot easily be mentally grasped, much less quantified.
Security strives to prevent the ‘Loss' of reputation, financial assets, customer goodwill, operations uptime, computing resources, personnel productivity, intellectual property, liability protection, and the list goes on. Some of these are obvious such as a worm which brings your operations to a grinding halt for two days. Others are not as obvious. Losing Personally Identifiable Information (PII) of customers would open the liability of lawsuits, potentially incur governmental fines, tarnish the corporate reputation, sour customer goodwill, and invoke long term recovery costs. Failure to meet Sarbanes-Oxley requirements may result in and having to cope with a CFO indictment and the associated difficulties of finding a temporary replacement while your executive spends an extended vacation in a federal penitentiary. A single security incident can inflict many different types of losses which in turn may vary wildly in overall impact.
The Evolving Security Landscape
All security programs exist in an evolving state. The enemies get smarter, move faster, and grow. The technology by which information flows rapidly changes. The very organization being protected and the assets within evolve over time. Regulations, customer expectations, experts' recommendations, and industry best-known-methods morph on a continual basis at a dizzying rate. The effectiveness and efficiency of security varies due to these external drivers as well as internal reasons.
So what does security look like over time? What are the key indicators? Here is my perspective. An organization will experience loss, period. If people are involved and any type of value is inherent, loss is expected. No surprise here. To get a better insight, let's apply the Greed Principle.
From a security perspective, greed is a double edged sword, both good and bad. Greed drives people to do bad things and break the rules for their benefit, but good as it gives continuing opportunities for security to catch these people. The Greed Principle simply states "Losses will increase if unchecked". This principle manifests itself in many different ways but basically, if someone is successful at finding a way of stealing $10 from you, they will continue unless something intervenes. In fact, they will increase the amount they steal over time. If it worked for $10, why not try $15 and so on. As greed is a strong emotional driver for the bad-guys, it provides more and more opportunities to the good-guys to detect them. Hence ‘greed' being both good and bad.
The greed cycle may be disrupted. Intervention may be in the form of additional controls, prevention, deterrence, social pressure, or direct interdiction just to name a few. Many different mechanisms can influence an attacker. Ultimately, unless something changes, greed guarantees losses will increase over time.
Instituting a decent security program is a surefire way to disrupt the unchecked losses. Even a completely mindless security measure can have a great impact. Ever wonder why sales associates say ‘hello' to you when you enter a boutique shop? Even if they don't have time to help you directly, they will make eye contact, greet you with a smile, and say hello. Is this for better customer service? Well yes that is one side benefit, but the primary function is to reduce the shoplifting. Most small stores don't have the money to maintain a security staff and shoplifting can be a major problem (last I checked, retail prices are ~15% higher to cover the costs of security and residual losses). The simple recognition of someone entering a store has shown to dramatically reduce the chances they will steal. In larger retailers, where they have a security staff, you may not get such a greeting (unless you wander into a predatory commission sales area).
The Security Maturity Model
Initial landing of a security program will affect the losses from attacks. But there is a price, namely the cost of security. Security spending bubbles before stabilizing in the maturity phase where it becomes more effective by lowering losses and more efficient by optimizing spending. Management usually has a firm hand in the reduction of spending, as they play an important part in keeping tension in the system.
So what do you get for your money? The amount of loss which did not occur, because of the influences of security, is the Loss Prevented. More loss prevented the better. But it is relative as the cost of security plays into the efficiency calculation. Basically the (Loss Prevented) - (Cost of Security) is one measure of value. A negative number is mostly unfavorable, indicating you are spending more on security than you are preventing. I wouldn't recommend that model unless what is being protected is irreplaceable (life safety, unique items, etc.).
Lastly, one other factor must be discussed. Sadly, the organization will still experience loss, regardless of how much you spend on security. This is Residual Loss. Nobody really likes to talk about this ugly fact of life. It is important. This is the gauge by which the organization determines what is acceptable.
Every security program must continually evolve to align to a changing landscape of attacker, methods, and alterations in the environment being protected. Over the long run, a good security program will get better and cost less.
I have rattled the ‘optimal security' saber before in previous blogs and it continues to hold true: Optimally, an organization should spend the amount of money on security which prevents enough loss to bring the residual losses to an acceptable level. Only management can decide exactly where the sweet-spot exists for any given moment.