Fortune: Check Point makes corporate routers and other computers more secure using software. Why software?

Gil Shwed : When I started Check Point in 1993, I found that the basic security inside routers was not enough. Today we still struggle to make security smarter; that’s the opposite of what hardware does. Whenever there is a new type of attack, we need to learn how to analyze it and differentiate between good connections and hackers.

You had sales last year of $1.3 billion. What are your big markets?

Finance is probably the largest, and then telecommunications. But we have more than 100,000 customers, from companies with 20 people to all of the Fortune 100.

Given your background in Israeli military intelligence, I’d think you’d stress sales to governments.

Like every Israeli, I was in the army. I wasn’t even an officer. I felt the government wasn’t an interesting market. I wanted to be completely civilian, completely commercial. Today we sell to everyone, including governments, but we don’t have any special focus on them.

Conventional wisdom today is that it is impossible to prevent an attack from a hacker like the Chinese military.

I don’t agree with that. We’ve done a decent job of creating a strong door so that nobody can penetrate it. That’s what the firewall does. And what the hackers are doing is trying to find ways around it. That’s akin to putting something in your pocket when you’re outside so that when you get in, there is something in your pocket that bugs the network. We are trying to do better screening for when you are coming through the gate, just like at the airport. When we find bad communication, we immediately block it.

You seem to avoid directly accusing China of wrongdoing.

I don’t know better than anyone else that it’s the Chinese or somebody else who’s behind these attacks. It is very easy to disguise yourself. We try to be on the good side. We are not hiring hackers; we are not trying to break in. We are trying to build strong walls.

So you’re a security guard, not a private investigator.

Exactly.

Check Point was a pioneer in the model of having headquarters in Israel but sales and marketing in the U.S. Is that still the model?

Today our workforce has actually become more Israeli. Part of that is the fact that there is better talent in Israel now.

Connected is an interview series with leaders of innovative organizations. Conversations are condensed and edited. For more Q&A and video, go to fortune.com/connected.

This story is from the September 16, 2013 issue of Fortune.