Author: Andrew LeCody 2015-08-18 23:56:51
Published on: 2015-08-18T23:56:51+00:00
In a message posted on the Bitcoin-dev mailing list, F L raised concerns about a blacklisting feature in Bitcoin XT that periodically downloads lists of Tor IP addresses. This feature, which is enabled by default and has a switch name that downplays what it does, has considerable privacy implications for users who are being prompted to use the software. The anti-DoS measures are easily bypassed and offer no protection. Connections are made over clearnet even when using a proxy or onlynet=tor, leaking connections on the P2P network with the real location of the node. Knowledge of this traffic, along with uptime metrics from bitnodes.io, can allow observers to easily correlate the location and identity of persons running Bitcoin nodes. Denial of service can also be used to crash and force a restart of an interesting node, making a new request to the blacklist endpoint via the clearnet on relaunch at the same time their P2P connections are made through a proxy. Requests to the blacklisting URL also use a custom Bitcoin XT user agent, which makes users distinct from other internet traffic if you have access to the endpoints logs. This feature is not included in Bitcoin Core.
Updated on: 2023-06-10T20:23:48.984630+00:00