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Re: How is NSA breaking so much crypto?

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Rich <rich@example.invalid> wrote:
> Jeffrey Goldberg <nobody@goldmark.org> wrote:
<snip>
>> 2. Are there good tools for generating safe primes that are available
>>    to developers?
> 
>> That is, there is an advantage to using unpopular groups. But most
>> software developers will pick a group and parameters out of some
>> standards document. If software developers using DH want to create
>> new groups, how can we help them to not make bad choices of primes.
> 
> There was a tiny bit of info in the paper about this, and my takeaway
> was that it was computationally difficult to verify that one did not
> pick a bad prime, which is why most implimentations ended up using the
> same one, or small set.  So they imply that simply 'picking your own'
> is not a reasonable solution (certianly not when one means picking a
> new good one with each connect, which would foil this attack).

My understanding it that _used_ to be the case 10 or 15 years. Back then
there was more uncertainty about safe primes. And, indeed, computers were
much slower. These days it makes eminent sense to generate your own DH
parameters. It's not even that difficult using, e.g., OpenSSL. It only takes
a few seconds or minutes.

I started avoiding common DH parameters and began generating random
parameters years ago for software and services I implement. I'm not a
cryptographer, but even I could read the writing on the wall.

One of the reasons SSL has been falling apart is because many of the
assumptions and best practives at the time of its creation--regarding cipher
agility, security of CBC, DH groups, etc--have been upended. I'm not saying
there weren't poor decisions originally. But I started reading this group
around 2000, and times sure have changed. The advice cryptographers gave
back then in many ways contradicts the advice given today. In some cases
(e.g. cipher agility, DH groups) best practice was overly cautious. In other
cases (e.g. CBC) best practice was insufficiently cautious. Notably, in 2000
this group saw more participation by practicing cryptographers--the ratio of
experts to idiots like myself was better.

Another concrete example, regarding DES:

	https://lwn.net/Articles/660486/

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How is NSA breaking so much crypto? Rich <rich@example.invalid> - 2015-10-15 01:44 +0000
  Re: How is NSA breaking so much crypto? "Chris M. Thomasson" <nospam@nospam.nospam> - 2015-10-15 12:04 -0700
    Re: How is NSA breaking so much crypto? wizzofozz <oscxxxxxxxaas@gmail.com> - 2015-10-15 22:24 +0200
      Re: How is NSA breaking so much crypto? William Unruh <unruh@invalid.ca> - 2015-10-15 23:13 +0000
        Re: How is NSA breaking so much crypto? <william@wilbur.25thandClement.com> - 2015-10-16 18:47 -0700
      Re: How is NSA breaking so much crypto? Jan Panteltje <pNaOnStPeAlMtje@yahoo.com> - 2015-10-16 10:09 +0000
    Re: How is NSA breaking so much crypto? Rich <rich@example.invalid> - 2015-10-15 22:38 +0000
    Re: How is NSA breaking so much crypto? William Unruh <unruh@invalid.ca> - 2015-10-15 23:11 +0000
      Re: How is NSA breaking so much crypto? Jakob Bohm <jb-usenet@wisemo.com> - 2015-10-16 02:08 +0200
        Re: How is NSA breaking so much crypto? Rich <rich@example.invalid> - 2015-10-16 00:25 +0000
          Re: How is NSA breaking so much crypto? Jakob Bohm <jb-usenet@wisemo.com> - 2015-10-16 04:04 +0200
  Re: How is NSA breaking so much crypto? Jeffrey Goldberg <nobody@goldmark.org> - 2015-10-16 11:53 -0500
    Re: How is NSA breaking so much crypto? Rich <rich@example.invalid> - 2015-10-16 17:54 +0000
      Re: How is NSA breaking so much crypto? <william@wilbur.25thandClement.com> - 2015-10-16 19:14 -0700
    Re: How is NSA breaking so much crypto? Jakob Bohm <jb-usenet@wisemo.com> - 2015-10-16 20:18 +0200
    Re: How is NSA breaking so much crypto? kg <kristiag+news@math.ntnu.no> - 2015-10-16 20:59 +0000
      Re: How is NSA breaking so much crypto? Jeffrey Goldberg <nobody@goldmark.org> - 2015-10-16 23:19 -0500
        Re: How is NSA breaking so much crypto? kg <kristiag+news@math.ntnu.no> - 2015-10-18 11:37 +0000
          Re: How is NSA breaking so much crypto? Jeffrey Goldberg <nobody@goldmark.org> - 2015-10-19 00:20 -0500
  Re: How is NSA breaking so much crypto? Anonymous <nobody@remailer.paranoici.org> - 2015-10-18 22:53 +0000
    Re: How is NSA breaking so much crypto? Rich <rich@example.invalid> - 2015-10-19 01:18 +0000
  Re: How is NSA breaking so much crypto? Noob <root@127.0.0.1> - 2015-10-30 08:45 +0100

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