Re: [Endymail] spam versus cleartext

[Pete Resnick <[e-mail]>]

On 9/7/14 11:09 AM, Phillip Hallam-Baker wrote:
> On Sun, Sep 7, 2014 at 9:21 AM, Pete Resnick<[e-mail]>  wrote:
>
>    
>> Along similar lines to what John Levine said,: Obviously doing e2e crypto
>> gets you signatures. Since we are blue-skying here, I think it is perfectly
>> plausible to say, "If you want to send me e2e encrypted messages, you also
>> have to send me signed messages, and you don't or your signature is not in
>> my contacts list already, your encrypted mail is going to bounce." I think
>> it's possible that in the fullness of time, many users go to a contact-list
>> model of email (a la IM) where the mail simply bounces unless it has a
>> signature that is already in the contacts list.
>>      
>
> I think that is right, but not the whole picture.
>    

A tangential up-level: I haven't gotten through all of the mail on the 
list yet (travel and other things have slowed me down), but I do notice 
that there has been quite a bit of "whole picture" discussion. I think 
that's fine, as blue-skying does involve thinking about how all of the 
pieces fit together. But as Stephen and I said in the first message, the 
thing we're looking for on this list is to "identify some bit(s) of work 
that the IETF could credibly do that'd improve the real-world end-to-end 
security and privacy of email. And note that 'credible' there requires 
stuff to be both technically sane and to have a sufficient set of 
capable folks interested and willing to do work." So while it's 
*possible* that a forklift replacement of email as we know it might be 
one of those "bits of work", separating out some smaller work items that 
could eventually be fit together into a shiny new system are probably 
the more interesting ideas. :-)

That said, a couple of questions that have been rattling around in my brain:

> I see endymail as a subset of mail. All mail should be encrypted at
> the message layer but only whitelisted mail would be e2e encrypted.
>
> This can be done automatically as follows:
>
>
> A) Some sort of discovery infrastructure maps email addresses to key hashes.
> B) Some sort of discovery infrastructure maps key hashes to keys.
>    

I've been wondering about this. When I think about using crypto (whether 
encryption or signatures), it seems like requiring a discovery mechanism 
was increasing the burden. For many of my correspondents, with whom I'm 
currently communicating in the clear, a TOFU key exchange in those 
emails (authenticated out-of-band) might be a plausible mechanism.

When we think about this, do we really need to assume that we either use 
the old or the new, and never the twain shall meet?

pr

-- 
Pete Resnick<http://www.qualcomm.com/~presnick/>
Qualcomm Technologies, Inc. - [phone]