The White House has issued an executive order revamping computer security policies to prevent classified documents from being linked to the Internet.

"Our nation's security requires information to be shared immediately with authorized users around the world but also requires sophisticated and vigilant means to ensure it is shared securely," President Barack Obama said. "Computer networks have individual and common vulnerabilities that require coordinated decisions on risk-management."

The executive order directs structural reform to protect classified information while sharing the information with those who need it to do their jobs.

Federal agencies will be responsible for ensuring classified documents are safeguarded in a way that is "consistent with appropriate protections for privacy and civil liberties," the order said.

The agencies, which will designate a senior official to oversee classified information-sharing and safeguarding, will implement an insider-threat detection and prevention program and perform self assessments of compliance with policy and standards.