Changes between Version 57 and Version 58 of TorWeeklyNews/2013/11


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Timestamp:
Sep 18, 2013, 1:13:33 PM (6 years ago)
Author:
harmony
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sent!

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  • TorWeeklyNews/2013/11

    v57 v58  
    33'''Editor:''' harmony
    44
    5 '''Status: FROZEN.''' New items should go in [wiki:TorWeeklyNews/2013/12 next week's edition]. Expected release time 2013-09-18 12:00 UTC.
    6 
    7 '''Subject:''' Tor Weekly News — September, 18th 2013
    8 
    9 {{{
    10 ========================================================================
    11 Tor Weekly News                                     September 18th, 2013
    12 ========================================================================
    13 
    14 Welcome to the twelfth issue of Tor Weekly News, the weekly newsletter
    15 that covers what’s happening in the closely-observed Tor community.
    16 
    17 Official response to QUICK ANT disclosure
    18 -----------------------------------------
    19 
    20 Another round of speculation regarding the attitude of state
    21 surveillance agencies towards the Tor network was provoked by a
    22 slide [1] featured in an edition of the Brazilian current-affairs show
    23 “Fantástico”, broadcast on September 8th [2]. The slide, leaked as part
    24 of the ongoing Snowden disclosures, appeared to show a tab in the
    25 alleged GCHQ [3] FLYING PIG surveillance interface labelled “Query
    26 QUICK ANT — Tor events QFD”. Users on Reddit [4] and Twitter [5] began
    27 to suggest possible attacks on Tor that might be managed through such an
    28 interface.
    29 
    30 Andrew Lewman posted an official response on the Tor blog [6] in which
    31 he reiterated that “it’s not clear what the NSA or GCHQ can or cannot
    32 do”, and that well-known theoretical attacks against the Tor network are
    33 clearly described on the project’s FAQ page [7].
    34 
    35 He further added that the tool in question was more likely to involve
    36 “some ‘Tor flow detector’ scripts that let them pick Tor flows out of a
    37 set of flows they’re looking at” than “anything to do with deanonymizing
    38 Tor users, except insofar as they might have traffic flows from both
    39 sides of the circuit in their database.”
    40 
    41 Finally, he remarked that instead of engaging in speculation based on
    42 limited evidence, “we’d rather spend our time developing Tor and
    43 conducting research to make a better Tor.”
    44 
    45    [1] https://people.torproject.org/~andrew/2013-09-10-quick-ant-tor-events-qfd.png
    46    [2] http://g1.globo.com/fantastico/noticia/2013/09/nsa-documents-show-united-states-spied-brazilian-oil-giant.html
    47    [3] https://twitter.com/ggreenwald/status/378185448293552128
    48    [4] http://www.reddit.com/r/TOR/comments/1m3jum/gchq_tor_events_capture/
    49    [5] https://twitter.com/jonathanmayer/status/377292928718499841
    50    [6] https://blog.torproject.org/blog/tor-nsa-gchq-and-quick-ant-speculation
    51    [7] https://www.torproject.org/docs/faq.html.en#AttacksOnOnionRouting
    52 
    53 Entry guards and linkability
    54 ----------------------------
    55 
    56 Leif Ryge pointed out [8] an issue with Tor’s current “entry guards”
    57 system, whereby connections entering Tor from different points on the
    58 same network could potentially be linked to an individual user based on
    59 the three entry nodes selected by that user’s Tor client, which remain
    60 constant for a period of 4-8 weeks [9].
    61 
    62 Leif suggested that “assuming this is an accurate assessment, wouldn’t
    63 it make sense to maintain separate sets of entry guards for each network
    64 that the user connects from?”
    65 
    66 Nick Mathewson replied [10] with an acknowledgement of the problem and a
    67 number of reasons why simply generating separate sets of guards might
    68 also harm a user’s anonymity: “You would *not*, for example, want to
    69 maintain a different set of entry guards for every IP that you receive,
    70 since if you did, a hostile DHCP server could feed you new IPs until you
    71 picked a hostile guard. Similarly, if you are a busy traveler who
    72 changes your view of what network you are on hundreds or thousands of
    73 times, your chance of picking a hostile guard would rise accordingly.”
    74 He also pointed out that “having a record in your state file of every
    75 network you have visited is not necessarily the best idea either.”
    76 
    77 Nick concluded by mentioning Roger Dingledine’s proposal to lower the
    78 number of entry guards selected by a client to one only, “to avoid the
    79 property of letting guard choices identify Tor clients”.
    80 
    81    [8] https://lists.torproject.org/pipermail/tor-dev/2013-September/005423.html
    82    [9] https://blog.torproject.org/blog/lifecycle-of-a-new-relay
    83   [10] https://lists.torproject.org/pipermail/tor-dev/2013-September/005424.html
    84 
    85 The lifecycle of a new relay: further research needed
    86 -----------------------------------------------------
    87 
    88 In response to some confusion on the part of relay operators over the
    89 apparently slow growth in the use of newly-established nodes by clients,
    90 Roger Dingledine posted on the Tor blog [11] a detailed account of how
    91 new relays, and the bandwidth they supply, are gradually integrated into
    92 the Tor network by directory authorities, bandwidth authorities, and
    93 clients themselves. Roger stressed that “the descriptions here are in
    94 part anecdotal”.
    95 
    96 Roger outlined the four broad phases that define the development of a
    97 relay within the network, and finished by offering a number of questions
    98 for further research, under a general rubric: “what do these phases look
    99 like with real-world data?” If you would like to contribute to the Tor
    100 community’s understanding of the interaction between individual relays
    101 and the network as a whole, please take a look both at the list of
    102 sample questions and at Tor’s publicly-available archive of metrics
    103 data [12], and see what you can find!
    104 
    105   [11] https://blog.torproject.org/blog/lifecycle-of-a-new-relay
    106   [12] https://metrics.torproject.org/data.html
    107 
    108 Food for thought
    109 ----------------
    110 
    111 “Back in the ancient pre-Tor days, at the height of the crypto wars,
    112 Ian Goldberg asked me at Financial Crypto in 1998 why we created onion
    113 routing. Not entirely facetiously I told him that the fascinating
    114 technological problems and the potential to better protect people and
    115 their activities was nice, but the real attraction was to create a
    116 context where people who were sure they should hate each other were
    117 forced to collaborate.” [13]
    118 
    119  — Paul Syverson
    120 
    121   [13] https://lists.torproject.org/pipermail/tor-talk/2013-September/030097.html
    122 
    123 Tor Help Desk Roundup
    124 ---------------------
    125 
    126 The Tor help desk received a request for assistance setting up
    127 Thunderbird to work with Tor. Thunderbird can be made to route
    128 connections through Tor using the TorBirdy add-on. Further information
    129 about using Tor with Thunderbird can be found on the wiki [14].
    130 
    131 Another user wrote to comment on the lack of OpenSUSE support on Tor’s
    132 rpm package page [15]. There is an open ticket concerning this issue,
    133 but it hasn’t seen activity for some months [16]. A new ticket was
    134 opened that addresses this concern more specifically [17].
    135 
    136   [14] https://trac.torproject.org/projects/tor/wiki/torbirdy#BeforeusingTorBirdy
    137   [15] https://www.torproject.org/docs/rpms.html
    138   [16] https://bugs.torproject.org/4389
    139   [17] https://bugs.torproject.org/9718
    140 
    141 Miscellaneous news
    142 ------------------
    143 
    144 The commitment level for the proposed Tor StackExchange page is hovering
    145 at 83%; it needs to reach 100% before it will be accepted into beta. If
    146 you think you will be able to contribute by answering questions from
    147 current or potential Tor users, please sign up! [18]
    148 
    149   [18] http://area51.stackexchange.com/proposals/56447/tor-online-anonymity-privacy-and-security
    150 
    151 Brian Callahan alerted relay operators running FreeBSD and OpenBSD to
    152 the release of ports updated to the new tor 0.2.4.17-rc [19].
    153 
    154 Christian Sturm then promptly announced the release of updated packages
    155 for NetBSD, DragonFly BSD, illumos, Minix, and “other systems
    156 potentially using pkgsrc” [20].
    157 
    158   [19] http://lists.nycbug.org/pipermail/tor-bsd/2013-September/000044.html
    159   [20] https://lists.torproject.org/pipermail/tor-talk/2013-September/030036.html
    160 
    161 Karsten Loesing updated tor’s GeoIP database to the newest version [21].
    162 
    163 Karsten also published the results of his memory usage test on a version
    164 of tor that reports additional statistics, which he conducted using the
    165 Shadow network simulator [22].
    166 
    167 Finally, Karsten asked for comments on his proposal to retire the old
    168 method of estimating user numbers on the metrics page over the next few
    169 weeks in favor of a more reliable, more efficient system (which has been
    170 in beta for some time already), and with it to remove the accumulated
    171 data associated with the older method [23].
    172 
    173   [21] https://bugs.torproject.org/9714
    174   [22] https://trac.torproject.org/projects/tor/ticket/7359#comment:18
    175   [23] https://lists.torproject.org/pipermail/tor-dev/2013-September/005443.html
    176 
    177 Fabio Pietrosanti announced that the available cipher suites for
    178 connections to tor2web.org have been updated to a much stronger
    179 set [24].
    180 
    181   [24] https://lists.torproject.org/pipermail/tor-talk/2013-September/030003.html
    182 
    183 Robert published the results of an investigation into different kinds of
    184 round-trip time (RTT) measurement, and their efficiency in building
    185 circuits through the Tor network [25].
    186 
    187   [25] https://lists.torproject.org/pipermail/tor-dev/2013-September/005440.html
    188 
    189 George Kadianakis asked for comments on his early draft of a proposal
    190 for different methods of migrating the Hidden Service protocol to a more
    191 secure version [26].
    192 
    193 George also pushed new versions of obfsproxy (0.2.3) and pyptlib
    194 (0.0.4) [27].
    195 
    196   [26] https://lists.torproject.org/pipermail/tor-dev/2013-September/005438.html
    197   [27] https://lists.torproject.org/pipermail/tor-dev/2013-September/005441.html
    198 
    199 In the course of a thread about the size of browser windows posing a
    200 fingerprinting threat [28], harmony discovered that users of Ubuntu’s
    201 Unity desktop should disable the “automaximize” behavior, as it can
    202 override one of Tor Browser’s anti-fingerprinting measures [29].
    203 
    204   [28] https://lists.torproject.org/pipermail/tor-talk/2013-September/030022.html
    205   [29] https://bugs.torproject.org/9738
    206 
    207 Tom Lowenthal submitted his monthly status report for August [30].
    208 
    209   [30] https://lists.torproject.org/pipermail/tor-reports/2013-September/000339.html
    210 
    211 Upcoming events
    212 ---------------
    213 
    214 Sep 29    | Colin at the Winnipeg Cryptoparty
    215           | Winnipeg, Manitoba, Canada
    216           | http://wiki.skullspace.ca/index.php/CryptoParty
    217           |
    218 Sep 29-01 | Tor at OpenITP Circumvention Tech Summit IV
    219           | Berlin, Germany
    220           | https://www.openitp.org/openitp/circumvention-tech-summit.html
    221           |
    222 Oct 09-10 | Andrew speaking at Secure Poland 2013
    223           | Warszawa, Poland
    224           | http://www.secure.edu.pl/
    225 
    226 
    227 This issue of Tor Weekly News has been assembled by harmony, Lunar,
    228 dope457, Matt Pagan, and Karsten Loesing.
    229 
    230 Want to continue reading TWN? Please help us create this newsletter.
    231 We still need more volunteers to watch the Tor community and report
    232 important news. Please see the project page [31], write down your
    233 name and subscribe to the team mailing list [32] if you want to
    234 get involved!
    235 
    236   [31] https://trac.torproject.org/projects/tor/wiki/TorWeeklyNews
    237   [32] https://lists.torproject.org/cgi-bin/mailman/listinfo/news-team
    238 }}}
     5'''Status:''' [https://lists.torproject.org/pipermail/tor-news/2013-September/000012.html Sent!]