The Security Tradeoffs

I have been doing some interviews lately, and the most fundamental IT Security question is probably the most difficult to answer.

What are the tradeoff of security? What is the direct impact of Security? For this question, lets talk about all the aspects of security (not just "IT Security").

There is an open debate if security is a tradeoff with privacy? Does an increase in security, make people lose their fundamental right of privacy or even liberty?

• Yes, in a way, more security would mean more vigilance and less anonymity
• No, because security controls can be present to protect privacy, especially "Personally Identifiable Information"

Hence, that is a valid debate.

However, the one point, no security guru would contradict or debate on is, "Security" is for sure a tradeoff between "Usability" and "Cost". An organization can only hope to control two of these variables, but never all three.

Image courtesy:   Technet Microsoft
Another good reference article

Update: 15-Oct-2012
A humorous video, which shows that privacy cannot exist without security, and vice-versa security cannot exist without privacy.

Update 17-Feb-2015:
Apple's Tim Cook speaks on this topic