Re: [plasma] why not web portal mail?

Stephen Farrell <> Fri, 08 April 2011 18:32 UTC

Return-Path: <>
Received: from localhost (localhost []) by (Postfix) with ESMTP id 4B72E3A6972 for <>; Fri, 8 Apr 2011 11:32:16 -0700 (PDT)
X-Virus-Scanned: amavisd-new at
X-Spam-Flag: NO
X-Spam-Score: -106.288
X-Spam-Status: No, score=-106.288 tagged_above=-999 required=5 tests=[AWL=0.312, BAYES_00=-2.599, RCVD_IN_DNSWL_MED=-4, USER_IN_WHITELIST=-100]
Received: from ([]) by localhost ( []) (amavisd-new, port 10024) with ESMTP id vwNADoHRWss3 for <>; Fri, 8 Apr 2011 11:32:13 -0700 (PDT)
Received: from ( []) by (Postfix) with ESMTP id 735F13A695D for <>; Fri, 8 Apr 2011 11:32:12 -0700 (PDT)
Received: from localhost (localhost []) by (Postfix) with ESMTP id 5644C3E4084; Fri, 8 Apr 2011 19:33:56 +0100 (IST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple;; h= content-transfer-encoding:content-type:in-reply-to:references :subject:mime-version:user-agent:from:date:message-id:received :received:x-virus-scanned; s=cs; t=1302287635; bh=7CqNUfZ++34pD6 +y0LjIWQcdO1UvV9O8vNSs9J0Jj+o=; b=NL5Qxx8tE/DXq0NP+2rjMNtHtnMnzZ kxtcehf/JWeJ328rLmvk3z6VbLeo74suE7Xv3nCy1DmgOXOa7NM0dxaRGTCv9/z7 dUwGeFqDW/qbEGIi9oS0ARBR4VtP120XxgeWO6rL90hLElaveKho5rIBypuEmfzx ClP/ELOjfcZwH1boSdUp2ZC2MmGGNi68ekZDBmA+oUTeR5H7QKF45wbUlt3PHVoK STSi4VNCrnWClmkkfP6mej8pzWqKBqAhAZlXE7fWLDL4feobv6PRj0C1E8Nfq3CW MP1YJdH8wCJukTwg6qXeSdJendRABxX++BhmPK3bSWTgvLtM9cpUW2/Q==
X-Virus-Scanned: Debian amavisd-new at
Received: from ([]) by localhost ( []) (amavisd-new, port 10027) with ESMTP id ZKC7yPh09tsl; Fri, 8 Apr 2011 19:33:55 +0100 (IST)
Received: from [] (unknown []) by (Postfix) with ESMTPSA id E82F33E406B; Fri, 8 Apr 2011 19:33:54 +0100 (IST)
Message-ID: <>
Date: Fri, 08 Apr 2011 19:33:54 +0100
From: Stephen Farrell <>
User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv: Gecko/20110223 Lightning/1.0b2 Thunderbird/3.1.8
MIME-Version: 1.0
To: Trevor Freeman <>
References: <>
In-Reply-To: <>
X-Enigmail-Version: 1.1.1
Content-Type: text/plain; charset="windows-1252"
Content-Transfer-Encoding: 8bit
Cc: "" <>
Subject: Re: [plasma] why not web portal mail?
X-Mailman-Version: 2.1.9
Precedence: list
List-Id: "The PoLicy Augmented S/Mime \(plasma\) bof discussion list." <>
List-Unsubscribe: <>, <>
List-Archive: <>
List-Post: <>
List-Help: <>
List-Subscribe: <>, <>
X-List-Received-Date: Fri, 08 Apr 2011 18:32:16 -0000

Hi Trevor,

On 06/04/11 20:33, Trevor Freeman wrote:
> Stephen Farrell asked why not use Web portal mail? Why do we need to
> develop plasma?
> I don’t think we concisely answered that question in the BoF and it is
> an important data point.

Thanks for trying now.

> The web portal mail products are used where there is no way to securely
> deliver sensitive mail to a recipient outside the sender’s organization.
> The message is held within the sender’s organization and a notification
> email is sent to the recipient.  The notification email contains a HTTPS
> URI to the original message with the sensitive content.  


> This model work Ok if it is bilateral communication e.g. doctor-patient
> where you want to reply to the sender. This has been deployed with my
> healthcare provider and we can exchange messages.   

Well, its also works fine for announcements, i.e. 1:N messages.

> However the
> notification email are very generic by design so it hard to find
> specific messages in your inbox other than by date and time sent. It
> also means useful features like inbox search don’t work as you only have
> the notification message in your inbox.

True. However, does that mean that you'd expect the UA search
function to be plasma-aware? If not, then won't the sensitive
information be vulnerable in whatever search DB the UA uses?
Maybe that's a question of defining the trust boundaries for
this, but given that the search may be on an IMAP server its
possibly complicated doing that in a secure way.

> This model fails totally if it’s multilateral communication where you
> want to reply all or forward to messages. 

Hmm. So that'd imply that forwarding etc. is an important
part of the proposed work? It strikes me that that's one of the
weakest aspects of generic s/mime (just from personal experience,
its not something I've gone out of my way to test). There'd also
be some pretty complex policy calculations to make to figure
out what can be forwarded to whom, I assume, so this seems like
a fairly complex area.

> The message never leaves the
> originators organization so you cannot originate new message as if it
> were from a recipient’s organization. This means for business to
> business scenario it would hinder the use of email for collaboration.

I don't get that at all. But never mind.

> With these limitations I think it’s clear that that plasma offers some
> significant benefits over web portal email.

Not that clear to me I'm afraid.

While you're arguing for plasma on this basis, to judge those arguments
people would need some kind of evidence that's a good bit better than
just an assertion. But I'm sure you guys are working on that.


> *Dr Trevor Freeman*  Senior Security Strategist
> *End to End Trust Team*
> <>**
> *Microsoft Trustworthy
> Computing*<> 
> _______________________________________________
> plasma mailing list