It will take several more years for the government to fully install high-tech systems to block computer intrusions, a drawn-out timeline that enables criminals to become more adept at stealing sensitive data, experts say.

As the Department of Homeland Security moves methodically to pare down and secure the approximately 2,400 network connections used every day by millions of federal workers around the world, experts suggest that technology already may be passing them by.

The department that's responsible for securing government systems other than military sites is slowly moving all the government's Internet and e-mail traffic into secure networks that eventually will be guarded by intrusion detection and prevention programs. The networks are known as Einstein 2 and Einstein 3.

Progress has been slow, however. Officials are trying to complete complex contracts with network vendors, work out technology issues and address privacy concerns involving how the monitoring will affect employees and public citizens.

The WikiLeaks release of more than a quarter-million sensitive diplomatic documents underscores the massive challenge ahead, as Homeland Security labors to build protections for all of the other, potentially more vulnerable U.S. agencies.