

Bitcoin: User's identity can be revealed much easier than thought - chriskanan
http://www.sciencedaily.com/releases/2014/11/141125074749.htm

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nine_k
The key part:

«In their new study, researchers at the Laboratory of Algorithmics, Cryptology
and Security of the University of Luxembourg have shown that Bitcoin does not
protect user's IP address and that it can be linked to the user's transactions
in real-time. To find this out, a hacker would need only a few computers and
about €1500 per month for server and traffic costs. Moreover, the popular
anonymization network "Tor" can do little to guarantee Bitcoin user's
anonymity, since it can be blocked easily.

The basic idea behind these findings is that Bitcoin entry nodes, to which the
user's computer connects in order to make a transaction, form a unique
identifier for the duration of user's session. This unique pattern can be
linked to a user's IP address. Moreover, transactions made during one session,
even those made via unrelated pseudonyms, can be linked together. With this
method, hackers can reveal up to 60 percent of the IP addresses behind the
transactions made over the Bitcoin network.»

