Changes between Version 37 and Version 38 of TorWeeklyNews/2013/10


Ignore:
Timestamp:
Sep 9, 2013, 3:07:45 PM (6 years ago)
Author:
lunar
Comment:

write about Tor crypto

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  • TorWeeklyNews/2013/10

    v37 v38  
    3838
    3939 XXX:Expand
     40
     41The future of Tor cryptography
     42------------------------------
     43
     44After the last round of revelations from Edward Snowden, described as
     45“explosive” by Bruce Schneier [XXX], several threads started on the
     46tor-talk mailing list to discuss Tor cryptography.
     47
     48A lot of what has been written is speculative at this point. But some
     49have raised concerns [XXX] about 1024 bit Diffie-Helmank key exchange [XXX].
     50This has already been adressed with the introduction of the “ntor”
     51handshake [XXX] in 0.2.4 and Nick Mathewson encourages everybody to
     52upgrade [XXX].
     53
     54Another thread [XXX] prompted Nick to summarize [XXX] its
     55views on the future of Tor cryptography. Regarding public keys, “with
     56Tor 0.2.4, forward secrecy uses 256-bit ECC, which is certainly
     57better, but RSA-1024 is still used in some places for signatures.
     58I want to fix all that in 0.2.5 — see proposal 220 [XXX], and George
     59Kadianakis’ draft hidden service improvements [XXX,XXX], and so forth.”
     60Regarding symmetric keys, Nick wrote: “We’re using AES128.  I’m hoping
     61to move to XSalsa20 or something like it.”
     62
     63The effort to design better cryptography for the Tor protocols is not
     64new. More than a year ago, Nick Mathewson presented proposal 202 [XXX]
     65outlining two possible new relay encryption protocols for Tor cells.
     66
     67A third question was raised [XXX] regarding the trust in algorithms
     68certified by the US NIST [XXX]. Nick speculations put aside, he also
     69emphasised that several NIST algorithms were “hard to implement
     70correctly” [XXX].
     71
     72Nick’s also plan to move away from NIST algorithms [XXX]: “Over the 0.2.5
     73series, I want to move even more things (including hidden services) to
     74curve25519 and its allies for public key crypto.  I also want to add
     75more hard-to-implement-wrong protocols to our mix: Salsa20 is looking
     76like a much better choice to me than AES nowadays, for instance.”
     77
     78Nick concluded one of his email with “these are interesting times for
     79crypto”. It sounds like a good way to put it.
     80
     81  [XXX] https://www.schneier.com/blog/archives/2013/09/the_nsa_is_brea.html
     82  [XXX] https://lists.torproject.org/pipermail/tor-talk/2013-September/029917.html
     83  [XXX] https://en.wikipedia.org/wiki/Diffie–Hellman_key_exchange
     84  [XXX] https://gitweb.torproject.org/torspec.git/blob_plain/HEAD:/proposals/216-ntor-handshake.txt
     85  [XXX] https://lists.torproject.org/pipermail/tor-talk/2013-September/029930.html
     86  [XXX] https://lists.torproject.org/pipermail/tor-talk/2013-September/029927.html
     87  [XXX] https://lists.torproject.org/pipermail/tor-talk/2013-September/029941.html
     88  [XXX] https://gitweb.torproject.org/torspec.git/blob_plain/HEAD:/proposals/220-ecc-id-keys.txt
     89  [XXX] https://lists.torproject.org/pipermail/tor-dev/2013-August/005279.html
     90  [XXX] https://lists.torproject.org/pipermail/tor-dev/2013-August/005280.html
     91  [XXX] https://gitweb.torproject.org/torspec.git/blob_plain/HEAD:/proposals/202-improved-relay-crypto.txt
     92  [XXX] https://lists.torproject.org/pipermail/tor-talk/2013-September/029933.html
     93  [XXX] https://en.wikipedia.org/wiki/National_Institute_of_Standards_and_Technology
     94  [XXX] https://lists.torproject.org/pipermail/tor-talk/2013-September/029937.html
     95  [XXX] https://lists.torproject.org/pipermail/tor-talk/2013-September/029929.html
    4096
    4197Toward a better performance measurement tool
     
    246302 * another research paper about hidden services https://lists.torproject.org/pipermail/tor-talk/2013-September/029856.html
    247303 * fox-it blog post https://lists.torproject.org/pipermail/tor-talk/2013-September/029862.html http://blog.fox-it.com/2013/09/05/large-botnet-cause-of-recent-tor-network-overload/
    248  * Tor encryption vs. latest revelations about NSA https://lists.torproject.org/pipermail/tor-talk/2013-September/029929.html https://lists.torproject.org/pipermail/tor-talk/2013-September/029930.html
    249304 * Testing flash proxy infrastructure https://lists.torproject.org/pipermail/tor-dev/2013-September/005402.html
    250305 * Quickly testing TOR using Chutney and Fluxcapacitor https://lists.torproject.org/pipermail/tor-dev/2013-September/005403.html