On the day Washington Post editor Bob Woodward disclosed that I. Lewis "Scooter" Libby wasn’t the first Bush administration official to reveal the secret identity of a CIA operative, the former New York Times reporter once at the center of the leak case continued to push for a shield law protecting journalists and their sources.

Judith Miller went to jail for 85 days this summer after she refused to tell a judge that Libby had told her the name of classified CIA operative Valerie Plame Wilson during a June 2003 interview. On Wednesday, she was the keynote speaker at a New York conference about blogging and journalism.

“I think we are in need of a federal shield law to protect the relationship between journalists and sources,” Miller told the conference, held by the Web log network Open Source Media . “I went to jail over the source of a story I never wrote.”

Miller may not have written a piece outing Plame Wilson, who is married to well-known critic of the Bush administration Amb. Joe Wilson, but other reporters, like columnist Robert Novak, did.

Libby resigned as Vice President Dick Cheney's chief of staff last month after he was indicted on charges of perjury, obstruction of justice and false statements relating to his grand jury testimony on the leak case.

According to Miller's testimony before the grand jury, the former White House official never referred to Plame Wilson by name during interviews for Miller's now well-known New York Times stories on the weapons of mass destruction case behind the war in Iraq

But Libby did refer to Joe Wilson's wife at the CIA, who volunteered him to go on a fact-finding mission to Africa, Miller said. Joe Wilson has charged that Libby ended his wife's career to get back at him for criticizing the Bush administration after he said he found no evidence Iraq tried to buy yellowcake uranium from Niger.

The bill Miller wants enacted is called the Free Flow of Information Act . It is currently making its way through Congress, although it's slow going and controversial. The Senate Judiciary Committee held a hearing on the measure on Oct. 19. Miller testified there.

Authored by Rep. Mike Pence and Sen. Richard Lugar , both Indiana Republicans, the legislation would shield any reporter or entity disseminating information through print, photographic, electronic or other means from having to reveal sources or be threatened with jail.

The only exception would be if a source gives information to a journalist about an imminent threat to national security. Op-ed columnists, humor writers and many bloggers wouldn't be covered by the law, which would replace current Justice Department guidelines designed to make news media subpoenas a tool of last resort.

The Justice Department opposes the legislation. Justice Department lawyer Chuck Rosenberg testified that since 1991, only 12 of 243 subpoenas issued under Justice Department guidelines to news media called for confidential source information.

"We seek information about confidential sources from reporters only when it really, really matters," he said. "What is broken about the way we are handling subpoenas to the media? ... I don't see anything in our work that justifies discarding 33 years of careful practice that has served the nation well."

Sen. Arlen Specter, R.-Pa., said Miller's imprisonment suggests something is broken. "Here you have a reporter in jail for 85 days and millions of Americans wonder why. I'm one of those," he said.

Miller said Wednesday she believes that the passage of the legislation is critical — not because it could have definitely helped her case, but because of the "threats to freedom of expression in this country, threats we all now face ... It's the danger of jailing journalists," she said.

Scrutiny of the mainstream media's work is important, Miller told FOXNews.com after her speech, but "not transparency when it comes to who your sources are.

"In investigative reporting, you cannot get around the use of anonymous sources. But you see if other people will go on the record with that same information," she said. "The whole purpose of getting news out depends on your sources."

After growing dissension between her and her editors about her reporting, Miller stepped down from her job at the Times last month, saying she could no longer be an effective reporter because she had "become the story" — something she hopes a shield law would prevent.

The Associated Press contributed to this report.