The government's program to match all airline passenger names against terrorist watch lists should not move forward into the testing phase, an advisory committee to the Transportation Security Administration said in a report released yesterday.

The TSA has said it planned to begin testing the airline security program, called Secure Flight, next month with two or more airlines. But the agency's advisory committee has cautioned against that move until the TSA can provide more documentation about how the program's stated goals can be achieved.

"Congress should prohibit the live testing of Secure Flight," the Sept. 19 document states, explaining that the working group was "not provided adequate information about the proposed program."

At the request of the TSA, the Secure Flight Working Group has evaluated security and privacy aspects of the program over the past nine months. Many of its members are privacy advocates who have criticized the program for matching passengers' reservation records with commercial databases commonly used for credit reports and retailer mailing lists.

Under the plan, each passenger's name would be compared against various government watch lists at the Terrorist Screening Center, a 24-hour facility run by the FBI that maintains databases of criminals and suspected and known terrorists.

"We asked for the criticism, we welcome it, and once we fully review the official report, we'll put it to use," said TSA spokeswoman Yolanda Clark.

The Department of Justice's inspector general found in a report in August that the screening center's managers did not think the technology infrastructure was adequately prepared to handle the large volume expected, 1.8 million daily airline passengers. The working group's report criticized the basic assumption of Secure Flight that efforts to learn more about passengers before they fly will result in snagging terrorists. The report states that "there is not sufficient intelligence to determine what characteristics indicate someone will be a threat" to an aircraft.

The report also said: "Intuition suggests that the more data collected, the more likely it is that the risk-identification process will succeed. However, there is no evidence available to validate this proposition, or to quantify how much more data about an individual would result in greater safety."

Marcia Hofmann, staff attorney at the Electronic Privacy Information Center, said the report shows that the program still has a long way to go in proving that it can work effectively while protecting passenger privacy. "The report shows the program suffers from very poor planning," Hofmann said. The TSA said earlier this week that the agency would not use commercial databases in its testing. Instead, the tests will allow the agency to match all passenger names against government watch lists. Currently, the airlines conduct name matches.

The move was welcomed by privacy groups -- but with reservations. "The TSA has not yet committed to permanently choosing to not use commercial data," said Tim Sparapani, legislative counsel of the American Civil Liberties Union. "They need to do so."

The report criticizes the program for lacking specifics on how the technology will perform the name matches and how it will address the likelihood of a high number of false matches. For example, there are now 270,000 entries in the watch list database, many of them aliases, the report said. Of the 270,000, about 30,000 to 40,000 are people on the "no fly" list who are not allowed to board domestic airplanes or flights heading to the United States because they are suspected terrorists or people with ties to suspected terrorist groups.

"One of the main challenges of Secure Flight is that the watch lists are primarily comprised of foreign nationals, while the domestic airline passengers the system applies to are overwhelmingly U.S. citizens," the report said. "This means TSA will collect information on millions of innocent Americans while looking for a few suspected foreigners. This fact heightens the importance of minimizing the privacy intrusion on those millions of innocent citizens."

Transportation Security Administration workers screen airline passengers at Denver International Airport.