Schmidt was nominated as vice chairman of the president's Critical Infrastructure Protection Board in December 2001, and served as deputy to former White House cybersecurity czar Richard Clarke. Clarke left his post in February.
A White House official confirmed Schmidt's resignation Tuesday, saying his departure would be effective at the end of the month. The official said Schmidt had left to return to the private sector.
Before coming to the White House, Schmidt wasat Microsoft.
Schmidt helped draft, unveiled in February. The government has recently reorganized its security efforts, placing responsibility for cybersecurity under the Department of Homeland Security.
The Information Technology Association of America said in a release that it was concerned "no single high-ranking Bush administration official has primary responsibility for the nation's cybersecurity."
ITAA President Harris N. Miller said in the release that the "cybersecurity issue is losing visibility inside the White House. Frankly, when everybody is in charge of an issue, nobody is in charge of the issue."