Criticism for the DHS at Wednesday's's hearing was not limited to that one issue, however. David Powner, director of IT management issues at the U.S. Government Accountability Office (GAO) noted that DHS had so far failed to establish a comprehensive plan for responding to cyberthreats against critical infrastructure.

He said that criminal groups, foreign intelligence services and terrorists all have the ability to launch disruptive physical and cyberattacks. While the DHS developed high-level plans for infrastructure protection, components that address Internet recovery are "incomplete", Powner said. In addition, while the DHS has begun working with private industry on processes for jointly responding to cyberattacks, the initiatives are "immature" and lack deadlines for completion, he said.

Also, hampering the department's efforts to establish a recovery plan is a lack of agreement over what the agency's role should be when a disruption does occur and when it should get involved, he said. In addition, the private sector has been reluctant to share information with the DHS because "it doesn't see a value in sharing" and lacks trust in the leadership, Powner said.

Those comments echoed a July GAO report, which said the government is not prepared to effectively coordinate public and private-sector plans for recovering from a major Internet attack. "Until these challenges are addressed, DHS will have difficulty achieving results in its role as a focal point for helping the Internet to recover from a major disruption," the report noted.

Meanwhile, in an unrelated development, the DHS Wednesday released a report highlighting the findings of its Cyber Storm Exercise involving simulated cyberattacks against the nation's critical infrastructure that were conducted in February. Among the key findings in the report is the need for a well-established chain of command in a time of crisis, the importance of information sharing across government and industry sectors and a better ability to correlate incident information across the two groups.