+ <div class="entry">
+ <div class="title"><a href="http://people.skolelinux.org/pere/blog/A_fist_full_of_non_anonymous_Bitcoins.html">A fist full of non-anonymous Bitcoins</a></div>
+ <div class="date">29th January 2014</div>
+ <div class="body"><p>Bitcoin is a incredible use of peer to peer communication and
+encryption, allowing direct and immediate money transfer without any
+central control. It is sometimes claimed to be ideal for illegal
+activity, which I believe is quite a long way from the truth. At least
+I would not conduct illegal money transfers using a system where the
+details of every transaction are kept forever. This point is
+investigated in an peer reviewed article in
+<a href="https://www.usenix.org/publications/login">USENIX ;login:</a>
+from December 2013, in the article
+"<a href="https://www.usenix.org/system/files/login/articles/03_meiklejohn-online.pdf">A
+Fistful of Bitcoins - Characterizing Payments Among Men with No
+Names</a>" by Sarah Meiklejohn, Marjori Pomarole,Grant Jordan, Kirill
+Levchenko, Damon McCoy, Geoffrey M. Voelker, and Stefan Savage. They
+analyse the transaction log in the Bitcoin system, using it to find
+addresses belong to individuals and organisations and follow the flow
+of money from both Bitcoin theft and trades on Silk Road to where the
+money end up. This is how they wrap up their article:</p>
+
+<p><blockquote>
+<p>"To demonstrate the usefulness of this type of analysis, we turned
+our attention to criminal activity. In the Bitcoin economy, criminal
+activity can appear in a number of forms, such as dealing drugs on
+Silk Road or simply stealing someone else’s bitcoins. We followed the
+flow of bitcoins out of Silk Road (in particular, from one notorious
+address) and from a number of highly publicized thefts to see whether
+we could track the bitcoins to known services. Although some of the
+thieves attempted to use sophisticated mixing techniques (or possibly
+mix services) to obscure the flow of bitcoins, for the most part
+tracking the bitcoins was quite straightforward, and we ultimately saw
+large quantities of bitcoins flow to a variety of exchanges directly
+from the point of theft (or the withdrawal from Silk Road).</p>
+
+<p>As acknowledged above, following stolen bitcoins to the point at
+which they are deposited into an exchange does not in itself identify
+the thief; however, it does enable further de-anonymization in the
+case in which certain agencies can determine (through, for example,
+subpoena power) the real-world owner of the account into which the
+stolen bitcoins were deposited. Because such exchanges seem to serve
+as chokepoints into and out of the Bitcoin economy (i.e., there are
+few alternative ways to cash out), we conclude that using Bitcoin for
+money laundering or other illicit purposes does not (at least at
+present) seem to be particularly attractive."</p>
+</blockquote><p>
+
+<p>These researches are not the first to analyse the Bitcoin
+transaction log. The 2011 paper
+"<a href="http://arxiv.org/abs/1107.4524">An Analysis of Anonymity in
+the Bitcoin System</A>" by Fergal Reid and Martin Harrigan is
+summarized like this:</p>
+
+<p><blockquote>
+"Anonymity in Bitcoin, a peer-to-peer electronic currency system, is a
+complicated issue. Within the system, users are identified by
+public-keys only. An attacker wishing to de-anonymize its users will
+attempt to construct the one-to-many mapping between users and
+public-keys and associate information external to the system with the
+users. Bitcoin tries to prevent this attack by storing the mapping of
+a user to his or her public-keys on that user's node only and by
+allowing each user to generate as many public-keys as required. In
+this chapter we consider the topological structure of two networks
+derived from Bitcoin's public transaction history. We show that the
+two networks have a non-trivial topological structure, provide
+complementary views of the Bitcoin system and have implications for
+anonymity. We combine these structures with external information and
+techniques such as context discovery and flow analysis to investigate
+an alleged theft of Bitcoins, which, at the time of the theft, had a
+market value of approximately half a million U.S. dollars."
+</blockquote></p>
+
+<p>I hope these references can help kill the urban myth that Bitcoin
+is anonymous. It isn't really a good fit for illegal activites. Use
+cash if you need to stay anonymous, at least until regular DNA
+sampling of notes and coins become the norm. :)</p>
+
+<p>As usual, if you use bitcoin and want to show your support of my
+activities, please send Bitcoin donations to my address
+<b><a href="bitcoin:15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b&label=PetterReinholdtsenBlog">15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b</a></b>.</p>
+</div>
+ <div class="tags">
+
+
+ Tags: <a href="http://people.skolelinux.org/pere/blog/tags/bitcoin">bitcoin</a>, <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>, <a href="http://people.skolelinux.org/pere/blog/tags/personvern">personvern</a>, <a href="http://people.skolelinux.org/pere/blog/tags/sikkerhet">sikkerhet</a>.
+
+
+ </div>
+ </div>
+ <div class="padding"></div>
+
<div class="entry">
<div class="title"><a href="http://people.skolelinux.org/pere/blog/New_chrpath_release_0_16.html">New chrpath release 0.16</a></div>
<div class="date">14th January 2014</div>
</div>
<div class="padding"></div>
- <div class="entry">
- <div class="title"><a href="http://people.skolelinux.org/pere/blog/Lets_make_a_wireless_community_network_in_Oslo_.html">Lets make a wireless community network in Oslo!</a></div>
- <div class="date">13th November 2013</div>
- <div class="body"><p>Today NUUG and Hackeriet announced
-<a href="http://www.nuug.no/news/Bli_med___bygge_dugnadsnett_for_alle_i_Oslo.shtml">our
-plans to join forces and create a wireless community network in
-Oslo</a>. The workshop to help people get started will take place
-Thursday 2013-11-28, but we already are collecting the geolocation of
-people joining forces to make this happen. We have
-<a href="https://github.com/petterreinholdtsen/meshfx-node/blob/master/oslo-nodes.geojson">9
-locations plotted on the map</a>, but we will need more before we have
-a connected mesh spread across Oslo. If this sound interesting to
-you, please join us at the workshop. If you are too impatient to wait
-15 days, please join us on the IRC channel
-<a href="irc://irc.freenode.net/%23nuug">#nuug on irc.freenode.net</a>
-right away. :)</p>
-</div>
- <div class="tags">
-
-
- Tags: <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>, <a href="http://people.skolelinux.org/pere/blog/tags/mesh network">mesh network</a>, <a href="http://people.skolelinux.org/pere/blog/tags/nuug">nuug</a>.
-
-
- </div>
- </div>
- <div class="padding"></div>
-
<p style="text-align: right;"><a href="index.rss"><img src="http://people.skolelinux.org/pere/blog/xml.gif" alt="RSS feed" width="36" height="14" /></a></p>
<div id="sidebar">
<li>2014
<ul>
-<li><a href="http://people.skolelinux.org/pere/blog/archive/2014/01/">January (1)</a></li>
+<li><a href="http://people.skolelinux.org/pere/blog/archive/2014/01/">January (2)</a></li>
</ul></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/bankid">bankid (4)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/bitcoin">bitcoin (7)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/bitcoin">bitcoin (8)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/bootsystem">bootsystem (13)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/drivstoffpriser">drivstoffpriser (4)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/english">english (233)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/english">english (234)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/fiksgatami">fiksgatami (21)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/opphavsrett">opphavsrett (45)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/personvern">personvern (67)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/personvern">personvern (68)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/raid">raid (1)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/scraperwiki">scraperwiki (2)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/sikkerhet">sikkerhet (33)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/sikkerhet">sikkerhet (34)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/sitesummary">sitesummary (4)</a></li>