RE: IDNA and U+08A1 and related cases (was: Re: Barry Leiba's Discuss on draft-ietf-json-i-json-05: (with DISCUSS and COMMENT))

Shawn Steele <Shawn.Steele@microsoft.com> Tue, 27 January 2015 01:17 UTC

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From: Shawn Steele <Shawn.Steele@microsoft.com>
To: Nico Williams <nico@cryptonector.com>, John C Klensin <john-ietf@jck.com>
Subject: RE: IDNA and U+08A1 and related cases (was: Re: Barry Leiba's Discuss on draft-ietf-json-i-json-05: (with DISCUSS and COMMENT))
Thread-Topic: IDNA and U+08A1 and related cases (was: Re: Barry Leiba's Discuss on draft-ietf-json-i-json-05: (with DISCUSS and COMMENT))
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Date: Tue, 27 Jan 2015 01:17:10 +0000
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Cc: Asmus Freytag <asmusf@ix.netcom.com>, "ietf@ietf.org" <ietf@ietf.org>, Pete Resnick <presnick@qti.qualcomm.com>, "idna-update@alvestrand.no" <idna-update@alvestrand.no>, The IESG <iesg@ietf.org>, Barry Leiba <barryleiba@computer.org>
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> As a corollary: more competition by [constrained] TLDs is good because 
> if -say- com. allows too many embarrassing confusable domains to be registered, 
> leading to noticeable and noticed phishing attacks, 

I think that underestimates the users....  But "does it matter"?

I've received 4 emails today that made it through whatever spam filters for whatever reason.  All 4 of them seemed to provide the opportunity for phishing attacks, and 0 of them leveraged IDN.  For that matter, they weren't even trying to be that clever with the ASCII paths.

I think the impact on phishing and confusables may be embarrassing perhaps, but don't have much true impact on security.  How many times have you mistyped a URL and ended up somewhere else?  Often with advertising and stuff trying to make a few cents off of the target URL typos?  

Too many companies send emails from "company@fulfillment.example.com" (totally random) or send you to "company.orderprocessing.example.com" and expect you to complete a link.  So phishing stuff with @secure.com is going to succeed.  They don't need confusable.  (I've even seen papers that suggest that scammers sometimes prefer obvious traps because they really want to get the gullible folks - obvious bad URLs could filter those out.)

-Shawn