CSO Online reports: The Tor Project said on Friday that the online anonymity network may go dark in coming days due to an attempt to incapacitate it.

The project’s leader Roger Dingledine aka “arma” drew attention to the possible outage on the project’s blog, flagging a tip-off that its directory authority servers — a handful of servers that form a consensus on which relays that Tor clients should use — may be the target of an upcoming “seizure”.

“The Tor Project has learned that there may be an attempt to incapacitate our network in the next few days through the seizure of specialized servers in the network called directory authorities,” Dingledine warned.

The wording of the alert suggests that the attacker is law enforcement rather than hackers. Should an attacker gain control of a majority of those servers, they would be able to vote in a fake Tor network.

As the project explains in its FAQ: “The directory authorities provide a signed list of all the known relays, and in that list are a set of certificates from each relay (self-signed by their identity key) specifying their keys, locations, exit policies, and so on. So unless the adversary can control a majority of the directory authorities (as of 2012 there are 8 directory authorities), he can’t trick the Tor client into using other Tor relays.”

A thread on Hacker News notes there are actually now nine directory authorities located across Europe and the US, so the attackers would need to gain control of five in order point Tor users to a phoney Tor network.

“We are taking steps now to ensure the safety of our users, and our system is already built to be redundant so that users maintain anonymity even if the network is attacked. Tor remains safe to use,” Dingledine noted.

It’s not clear what the motivation is for the possible seizure, nor which authority may be behind it. However, there is speculation it may be related to the Sony Pictures investigation due to the hackers having used Tor in the attack. [Continue reading…]

The Register today reports: As foreshadowed last week, Tor network exit nodes have gone down after what appear to be raids by law enforcement authorities.

Thomas White (@CthulhuSec) warned users to steer clear of his Tor servers after he lost control following what he’s called “unusual activity” that meant “I have now lost control of all servers under the ISP and my account has been suspended,” White wrote in an update on the Tor mailing list.

“Having reviewed the last available information of the sensors, the chassis of the servers was opened and an unknown USB device was plugged in only 30-60 seconds before the connection was broken.

“From experience I know this trend of activity is similar to the protocol of sophisticated law enforcement who carry out a search and seizure of running servers.”

White said users should treat the servers as hostile until control was regained signified by a PGP signed message from himself.

He also urged them not to jump to conclusions about the identity of any possible agency nor harbour concern for the integrity of the Tor network.