The materials related to Tor are not allowed to be released to the public.
A highly anticipated discussion on how to detect users of Internet anonymity service 'Tor' has been pulled down from the upcoming Black Hat security conference, which will be held from August 2-7 2014 in Las Vegas, US.
The latest decision comes at the request of legal counsel at Carnegie Mellon University's Software Engineering Institute (SEI), as the materials under discussion have not been permitted for public release.
According to Black Hat, one of the selected discussions, 'You Don't Have to be the NSA to Break Tor: Deanonymizing Users on a Budget' by CERT/Carnegie Mellon researcher Alexander Volynkin was scheduled for a briefing at the event.
A legal counsel for the SEI said in a statement: "Unfortunately, Mr. Volynkin will not be able to speak at the conference since the materials that he would be speaking about have not yet approved by CMU/SEI for public release."
Short for the Onion Router, Tor is a network of distributed nodes that beefs up privacy by encrypting an individual's browsing traffic and routing it through random alternative servers.
Originally developed by the US Naval Research Laboratory, Tor is widely deployed by both cybercriminals and those with legal interests in maintaining their anonymity, including dissidents and reporters.
The TOR Project co-founder, Roger Dingledine, said that some of Volynkin's materials had been informally shared with his organisation and it would now work with CERT to do a synchronised revelation around the findings, maybe later this week.
"Researchers who have told us about bugs in the past have found us pretty helpful in fixing issues and generally positive to work with," Dingledine added.