CSOonline published an article entitled, "What Are the Most Overrated Security Technologies?" At the head of the list are, no surprise, Anti-Virus and Firewalls.
Anti-Virus – signature based anti-virus products simply cannot keep up with the speed and creativity of the attackers. What's needed is better behavior anomaly based approaches to complement traditional anti-virus products.
Firewalls – The article talks about the disappearing perimeter, but that is less than half the story. The bigger issue is that traditional firewalls, using stateful inspection technology introduced by Check Point over 15 years ago, simply cannot control the hundreds and hundreds of "Web 2.0" applications. I've written about or referenced "Next Generation Firewalls" here, here, here, here, and here.
IAM and multi-factor authentication – Perhaps IAM and multi-factor authentication belong on the list. But the rationale in the article was vague. The biggest issue I see with access management is deciding on groups and managing access rights. I've seen companies with over 2,000 groups – clearly an administrative and operational nightmare I see access management merging with network security as network security products become more application, content, and user aware. Then you can start by watching what people actually do in practice rather than theorize about how groups should be organized.
NAC – The article talks about the high deployment and ongoing administrative and operational costs outweighing the benefits. Another important issue is that NAC does not address the current high risk threats. The theory in 2006, somewhat but not overly simplified, was that if we checked the end point device to make sure its anti-virus signatures and patches were up-to-date before letting it on the network, we would reduce worms from spreading.
At present in practice, (a) worms are not major security risk, (b) while patches are important, up-to-date anti-virus signatures does not significantly reduce risk, and (c) an end point can just as easily be compromised when it's already on the network.
A combination of (yes again) Next Generation Firewalls for large locations and data centers, and cloud-based Secure Web Gateways for remote offices and traveling laptop users will provide much more effective risk reduction.