Subject: Re: [smime] [pkix] Identified Work Items and Discussion Summary (was: possible new pkix and/or smime work)

From: "John R Levine" <[email-masked]>
Date: 1 Apr 2016 12:43:27 -0400

> If people are unaware, protection of email headers (for PGP) is
> progressing at https://modernpgp.org/memoryhole/ (although it may be a
> bit stalled.)

This looks like the usual approach of wrapping the message in an outer 
message with all of the headers genericised.  Ned Freed has said this has 
severe patent problems.  I don't know the details.

Regards,
John Levine, [email-masked], Taughannock Networks, Trumansburg NY
Please consider the environment before reading this e-mail.

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From: Wei Chuang <[email-masked]>
Date: Fri, 1 Apr 2016 10:47:08 -0700

There's also an experimental RFC7508 "Securing Header Fields with S/MIME"
plus RFC5751 mentions using message/rfc822 though that is not completely
specified.  One issue likely common with these approaches is keeping
private the sender and recipient(s).  I've pitched the idea of doing some
form of onion routing to mitigate that.  Hopefully these are things folks
would be interested in pursuing.

-Wei

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From: Tom Ritter <[email-masked]>
Date: Fri, 1 Apr 2016 11:36:02 -0500

-tom

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From: Tom Ritter <[email-masked]>
Date: Fri, 1 Apr 2016 13:16:21 -0500

On 1 April 2016 at 12:47, Wei Chuang <[email-masked]> wrote:
> specified.  One issue likely common with these approaches is keeping private
> the sender and recipient(s).  I've pitched the idea of doing some form of
> onion routing to mitigate that.  Hopefully these are things folks would be
> interested in pursuing.

I'm super interested in that.

I've been interested and worked casually on mix networks for a bit,
for strong anonymity. But there are lots of problems there, including
reliability (and throughput) of nodes, abuse, and of course the 'going
dark on spam' problem . Lately I've been thinking about something
weaker and potentially more deployable.

Model it as four parties at play: Sender, Receiver, Sender Provider,
Receiver Provider. Right now each party sees everything - goal is to
reduce that.

One idea I've had is that each provider can publish a
[email-masked] address.  You encrypt a message to
[email-masked] specifying [email-masked] as the recipient with
the body additionally encrypted (or not) to Alice. Google decrypts and
then forwards to Alice. This makes the Recipient private from the
Sender Provider, and doesn't impact any sort of incoming spam
controls.  (It does impact outgoing spam controls to a certain
degree.)

Another idea is that the sending provider can strip all identifying
information from the message as it passes through them. The
information is contained inside the encrypted envelope to the final
recipient. Sending provider will still know who's sending the message
(SMTP authentication) - but the Receiving Provider doesn't learn the
Sender.  You've got lots of concerns about impersonation here, but I
think we could device a cryptographic protocol that gives the Sending
Provider assurance the Sender isn't trying to masquerade as someone
else. (The simplest one would just have the Sending Provider encrypt
the Sender to the Recipient.)

-tom

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From: Stephen Farrell <[email-masked]>
Date: Mon, 4 Apr 2016 20:21:45 +0100

Hiya,

On 31/03/16 20:08, Stephen Farrell wrote:
> 
> And separately, I'd like to try get interested folks who'll be
> at IETF95 together for a chat if we can.

If you're interested in this and at IETF95, I've booked a room
(Paraiso, 5th floor) for Thursday 1945 to chat about whether or
not we seem to have enough work and interest to charter a WG
for some of these. I think we should aim to be quick about that
so I've just booked 30 minutes. Chat can of course continue
after that at bits'n'bytes or elsewhere.

Please send me an offlist reply to this if you'd like to take
part, just for room-size.

Thanks,
S.

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From: Stephen Farrell <[email-masked]>
Date: Wed, 6 Apr 2016 18:40:57 +0100

Hiya,

I got 10 folks saying they'll come which is the capacity of the
room and since I should probably also be there we're changing
the room to Atlantico A at the same time (1945 Thu). That holds
about 40 which should be plenty so no more need to ping me and
say you'll come, just turn up if in B-A and interested.

Cheers,
S

On 04/04/16 20:21, Stephen Farrell wrote:
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