FILE - In this Dec. 4, 2013, file photo, House Oversight and Government Reform Committee Chairman Rep. Darrell Issa, R-Calif., right, confers with the committee's ranking Democrat, Rep. Elijah Cummings, D-Md., on Capitol Hill in Washington, before the start of the committee's hearing on the implementation of the Affordable Care Acts HealthCare.gov website. The top cybersecurity officer for the federal Health and Human Services department was concerned about potential vulnerabilities ahead of the launch of the Obama administrations health care website. Issa, investigating the chaotic rollout of the website contends the administration risked the personal information of millions of Americans in its zeal to meet a self-imposed Oct. 1 deadline. Cummings says the administration addressed the potential security issues through added vigilance instituted before the site went live. (AP Photo/J. Scott Applewhite, File)

WASHINGTON (AP) Cybersecurity concerns over President Barack Obama's health care website have been cleared up through testing, a government security professional who initially had qualms about the system assured lawmakers Thursday.

But a congressional hearing featuring three senior technology experts from within the Health and Human Services Department also revealed a broader internal debate before the hapless launch of HealthCare.gov last fall.

One of the witnesses, HHS Chief Information Officer Frank Baitman, said he personally brought security issues to the attention of the department's second-in-command, Bill Corr, as well as another senior official. It's unclear what, if anything, Secretary Kathleen Sebelius and White House officials were told.

The maddening technical problems that frustrated consumers for weeks as they tried to sign up for health insurance would pale in comparison if a serious security breach compromised the names, Social Security numbers, incomes and other personal information of millions of Americans.

Republicans on the House Oversight and Government Reform Committee are trying to build a case that the administration recklessly ignored security concerns to meet a self-imposed Oct. 1 deadline for flipping the switch. The administration and Democratic lawmakers say all issues were addressed through special vigilance instituted just before the launch. While Republicans have raised questions, they have yet to find a smoking gun.

Officials told the committee no attempted attack by hackers has succeeded, although a shadowy group calling itself "Destroy Obamacare" has tried. There have been 13 known inadvertent exposures or disclosures of information.

The root of the controversy is that the health care site did not get full security testing, as is the usual practice with federal systems before they are put into use. The technology was getting constant tweaks that precluded a final assessment. It also was prone to crashing.

However, Medicare's top cybersecurity official testified Thursday that the revamped website passed full security tests Dec. 18, easing her earlier concerns about vulnerabilities. Teresa Fryer, chief information security officer at the Centers for Medicare and Medicaid Services, had initially balked at the site going live.

She said Thursday she would now recommend full operational and security certification for the site, which currently has what amounts to a six-month permit. The Medicare agency is responsible for expanding coverage to the uninsured under the health care law.

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Health care website passed recent test