Boston (AP)  -- A federal judge has lifted a gag order on three MIT students who were barred from talking publicly about security flaws they discovered in the MBTA's automated fare system, even as a lawyer for the transit agency acknowledged the CharlieTicket system has security flaws.

The lawyer asked Judge George O'Toole Jr. to impose a five month injunction blocking the students from revealing anything publicly about the security system. O'Toole rejected the request.

The MBTA said a 30-page security analysis turned over to the agency by the students convinced the T the CharlieTicket system was flawed.

The students had hoped to present their findings on the MBTA's security flaws earlier this month at Defcon, an annual computer hackers' conference.