The Pentagon is inviting certain hackers to try to penetrate its security system. Defense Department leaders want to get a handle on where flaws exist, and how to fix them. As such, the new “Hack the Pentagon” pilot program would allow vetted hackers to “conduct vulnerability identification and analysis” on the department’s Web sites. The program is patterned after similar exercises conducted by private businesses. “I am confident this innovative initiative will strengthen our digital defenses and ultimately enhance our national security,” Defense Secretary Ash Carter said March 2.