MONTEREY, Calif. -- More than 100 cyber experts and leaders gathered here recently for Cyber Endeavour, an annual symposium designed to call attention to the ever-changing challenges of securing military and civilian networks from cyber attacks.

The three-day conference focused on emerging threats to "cyber cities" and how a potential attack could impact national security should the worst occur: the crippling of key infrastructure.

"Cyber cities represent the highest level of advancement in a civilization," said Dr. John Arquilla of the Naval Postgraduate School. "We have to develop our own resilience against cyber attacks for today and tomorrow."

The latest population statistics show about 54 percent of the world's population is concentrated around urban areas, with that number projected to grow closer to 70 percent by 2050.

Cyber experts point out that much of the infrastructure for cities across the globe, such as power grids and water treatment plants, predates the Internet, which poses a different set of challenges for those trying to protect it from cyber attacks.

"We are taking advanced technology and connecting it to old infrastructure," said Arquilla. "This opens up the possibility for cities becoming vulnerable to strategic attack."

Virtual cyber ranges are becoming an increasingly important training tool for cyber warriors to train, test and implement cyber security. One of the best training locations is the National Cyber Range in Orlando, Florida.

Range director Peter Christensen said his venue provides the most realistic interpretation of cyberspace, where operators can test the effectiveness of cyber defenses and cyber weapons.

"Cyber cities will be fertile ground to be exploited," said Christensen. "Vulnerabilities must be identified in development and not during deployment. This is why cyber ranges are so important."

A panel discussion during Cyber Endeavour focused on defining a cyber city.

"I think what we are talking about is the use of automation to support the population density that we now have in an urban environment," said Cmdr. Pablo Breuer of the Naval Postgraduate School.

Cyber warriors must rely on variety of skills to successfully support and defend cyber cities, including the abilities to anticipate, predict and assess threats in a team environment.

The Army Reserve's 335th Signal Command (Theater), based in East Point, Georgia., is responsible for organizing, training, equipping and manning all USAR cyber units.

With the rapid growth in the demand for cyber skills, recruiting and retaining the next generation of cyber warriors has become a key objective for the command.

"In positioning our units in recruiting, a key aspect to our objectives is drawing from a variety of civilian populations so as to bring their unique skill sets into our military capabilities," said Col. James Chatfield, the 335th's chief of operations.

Representatives from the private sector also participated in Cyber Endeavour, illustrating the important role industry plays in defending cyber cities, for both the military and civilian sectors.

Partnerships with government entities in the cybersecurity realm will be critical in the effort to reduce the likelihood of a breach happening, said Jim Patterson of the American International Group.

Cyber Endeavour is sponsored jointly by the 335th, the Department of Defense Information Operations Center for Research, and the Defense Innovation Unit Experimental.