Re: [idn] nameprep2 and the slash homograph issue

Erik van der Poel <erik@vanderpoel.org> Wed, 02 March 2005 01:09 UTC

Received: from psg.com (mailnull@psg.com [147.28.0.62]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id UAA29980 for <idn-archive@lists.ietf.org>; Tue, 1 Mar 2005 20:09:59 -0500 (EST)
Received: from majordom by psg.com with local (Exim 4.44 (FreeBSD)) id 1D6IIy-0001gd-OK for idn-data@psg.com; Wed, 02 Mar 2005 01:05:36 +0000
Received: from [207.115.63.77] (helo=pimout1-ext.prodigy.net) by psg.com with esmtp (Exim 4.44 (FreeBSD)) id 1D6IIw-0001fl-Np for idn@ops.ietf.org; Wed, 02 Mar 2005 01:05:35 +0000
Received: from [10.1.1.2] (adsl-64-174-147-206.dsl.sntc01.pacbell.net [64.174.147.206]) by pimout1-ext.prodigy.net (8.12.10 milter /8.12.10) with ESMTP id j2215UhV268984; Tue, 1 Mar 2005 20:05:30 -0500
Message-ID: <42251159.1040300@vanderpoel.org>
Date: Tue, 01 Mar 2005 17:05:29 -0800
From: Erik van der Poel <erik@vanderpoel.org>
User-Agent: Mozilla Thunderbird 1.0 (X11/20041206)
X-Accept-Language: en-us, en
MIME-Version: 1.0
To: Gervase Markham <gerv@mozilla.org>
CC: idn@ops.ietf.org
Subject: Re: [idn] nameprep2 and the slash homograph issue
References: <421B8484.3070802@vanderpoel.org> <20050223072837.GA21463~@nicemice.net> <D872CCF059514053ECF8A198@scan.jck.com> <20050223105244.GE21463~@nicemice.net> <421CA114.9090302@vanderpoel.org> <20050224081721.GB12336~@nicemice.net> <421DEDFF.2000300@vanderpoel.org> <4225A87B.7030204@mozilla.org>
In-Reply-To: <4225A87B.7030204@mozilla.org>
Content-Type: text/plain; charset="ISO-8859-1"; format="flowed"
Content-Transfer-Encoding: 7bit
X-Spam-Checker-Version: SpamAssassin 3.0.1 (2004-10-22) on psg.com
X-Spam-Status: No, score=-2.2 required=5.0 tests=AWL,BAYES_00,WHY_WAIT autolearn=no version=3.0.1
Sender: owner-idn@ops.ietf.org
Precedence: bulk
Content-Transfer-Encoding: 7bit

Gervase Markham wrote:
> While security-conscious users are always less at risk than ordinary 
> users, thinking in terms of a tool is IMO wrong.

Perhaps I was wrong to use the word "tool". There is a fundamental 
tension between security and user-friendliness. Some applications and 
vendors have a history of making their user interfaces *too* friendly, 
thereby neglecting to warn users of potential security risks. Other 
vendors have tried hard to strike a balance between security and 
seamlessness. I believe Netscape and Mozilla have been in this camp 
since Day One.

I hope that mozilla.org will deploy a better solution than the TLD and 
domain black/whitelists that have been discussed.

>> It would offer to display domain names in the 
>> safe order, i.e. left-to-right for users whose main language is 
>> left-to-right.
> 
> The problem this is supposed to mitigate is mitigated in Firefox by the 
> domain-only indicator in the status bar.

I just double-checked Firefox 1.0.1, and it just says "Done" at the 
lower left. Then I tried a secure (https) site, and, lo and behold, I 
saw the "domain-only" indicator at the lower right, next to the padlock 
icon. This is very good news (to me). And thank you for educating this 
particular user (me) about this security issue. As I have often said, 
education is key.

A couple of questions/comments: It might be nice to have this 
domain-only display even for non-secure sites (http). Also, do you know 
what happens if the domain name is very long? Finally, do you have any 
thoughts about the slash homograph problem? Thanks.

>> In addition, such a tool would offer to display domain names in a 
>> clear font, unlike the sans-serif that is commonly used today. This 
>> would make the distinction between lowercase l and digit 1 clearer. 
> 
> Assuming we could determine such a font, why would we not always use it? 
> Why wait for a tool to be deployed?

Indeed, why wait? I filed a bug a while ago:

https://bugzilla.mozilla.org/show_bug.cgi?id=282079

My feeling is that a sans-serif font (such as Arial) places the 
characters too close to each other and does not have the serifs that 
often serve to distinguish the characters better. How about a fixed 
width font with serifs, such as Courier New?

Erik