public inbox for bitcoindev@googlegroups.com
 help / color / mirror / Atom feed
From: Gregory Maxwell <gmaxwell@gmail•com>
To: Luke-Jr <luke@dashjr•org>
Cc: Bitcoin Development <bitcoin-development@lists•sourceforge.net>
Subject: Re: [Bitcoin-development] Payment protocol for onion URLs.
Date: Fri, 25 Oct 2013 21:06:48 -0700	[thread overview]
Message-ID: <CAAS2fgTWjPCdAZB22GdRWkfULS-L9XaqYRZqB=dcbGV1+My3nA@mail.gmail.com> (raw)
In-Reply-To: <201310260341.41613.luke@dashjr.org>

On Fri, Oct 25, 2013 at 8:41 PM, Luke-Jr <luke@dashjr•org> wrote:
> Is there any point to additional encryption over tor (which afaik is already
> encrypted end-to-end)? Is there a safe way to make this work through tor entry
> nodes/gateways?

The x.509 in the payment protocol itself is for authentication and
non-repudiation, not confidentiality.

It's used to sign the payment request so that later there is
cryptographic evidence in the event of a dispute:
"He didn't send me my alpaca socks!" "Thats not the address I told you to pay!"
"He told me he'd send my 99 red-balloons, not just one!"  "No way,
that was the price for 1 red-balloon!"

Just using SSL or .onion (or whatever else) gets you confidentiality
and authentication.  Neither of these things get you non-repudiation.

> It'd be nice to have a way to support namecoin-provided keys too...

The payment protocol is extensible, so I hope that someday someone
will support namecoin authenticated messages (but note: this requires
namecoin to support trust-free SPV resolvers, otherwise there is no
way to extract a compact proof that can be stuck into a payment
request) and GPG authenticated messages.

But those things will require a fair amount of code (even fixing the
namecoin protocol in the nmc case), and GPG could be done just by
externally signing the actual payment request like you'd sign any
file... and considering the sorry state of their _practical_
usability, I don't think they're worth doing at this time.

By contrast, I _think_ the tor onion support would require only a
relatively few lines of code since it could just be the existing x.509
mechanism with just a simple special validation rule for .onion, plus
a little tool to repack the keys.  I think it would easily be more
widely used than namecoin (though probably both would not really be
used, as gavin notes).

w/ Gavin's comments I'll go check in with the tor folks and see if
anyone has ever though of doing this before and if there is already a
canonical structure for the x.509 certs used in this way.



  reply	other threads:[~2013-10-26  4:06 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-10-26  3:31 Gregory Maxwell
2013-10-26  3:41 ` Luke-Jr
2013-10-26  4:06   ` Gregory Maxwell [this message]
2013-10-28 12:14     ` Adam Back
2013-10-28 13:21       ` Mike Hearn
2013-10-26  3:55 ` Gavin Andresen
2013-10-26  4:15 ` Peter Todd
2013-10-28  5:58 ` John Dillon
2013-10-28 19:37   ` Jeremy Spilman
2013-10-31  0:44     ` Peter Todd

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to='CAAS2fgTWjPCdAZB22GdRWkfULS-L9XaqYRZqB=dcbGV1+My3nA@mail.gmail.com' \
    --to=gmaxwell@gmail$(echo .)com \
    --cc=bitcoin-development@lists$(echo .)sourceforge.net \
    --cc=luke@dashjr$(echo .)org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox