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[TLS] Fw: I-D Action: draft-ietf-tls-prohibiting-rc4-01.txt

"Blumenthal, Uri - 0558 - MITLL" <uri@ll.mit.edu> Fri, 24 October 2014 14:54 UTC

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From: "Blumenthal, Uri - 0558 - MITLL" <uri@ll.mit.edu>
To: "'tls@ietf.org'" <tls@ietf.org>
Thread-Topic: [TLS] I-D Action: draft-ietf-tls-prohibiting-rc4-01.txt
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Date: Fri, 24 Oct 2014 14:54:32 +0000
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Subject: [TLS] Fw: I-D Action: draft-ietf-tls-prohibiting-rc4-01.txt
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--
Regards,
Uri Blumenthal                            Voice: (781) 981-1638
Cyber Systems and Technology   Fax:   (781) 981-0186
MIT Lincoln Laboratory                Cell:  (339) 223-5363
244 Wood Street, Lexington, MA 02420-9185       

Web:  http://www.ll.mit.edu/CST/
MIT LL Root CA:  <https://www.ll.mit.edu/labcertificateauthority.html>

----- Original Message -----
From: Blumenthal, Uri - 0558 - MITLL
Sent: Friday, October 24, 2014 10:50 AM
To: 'rsalz@akamai.com' <rsalz@akamai.com>
Subject: Re: [TLS] I-D Action: draft-ietf-tls-prohibiting-rc4-01.txt

I disagree. In case of SMTP STARTTLS something *is* better than nothing. It is not about false sense of security - it is about making the adversary's job harder when possible as much as possible; realizing that sometimes what's possible is not going to be AES256-hard.

P.S. In that case/scenario even ROT13 is better than nothing.

--
Regards,
Uri Blumenthal                            Voice: (781) 981-1638
Cyber Systems and Technology   Fax:   (781) 981-0186
MIT Lincoln Laboratory                Cell:  (339) 223-5363
244 Wood Street, Lexington, MA 02420-9185       

Web:  http://www.ll.mit.edu/CST/
MIT LL Root CA:  <https://www.ll.mit.edu/labcertificateauthority.html>

----- Original Message -----
From: Salz, Rich [mailto:rsalz@akamai.com]
Sent: Friday, October 24, 2014 10:31 AM
To: tls@ietf.org <tls@ietf.org>
Subject: Re: [TLS] I-D Action: draft-ietf-tls-prohibiting-rc4-01.txt

> Leaving a cipher suite out is only practical once it is no longer the best shared
> cipher with any peers.  

I don't agree with this blanket statement.  Sometimes nothing trumps "something is better than nothing."

When the IETF's leading cryptographers say not to use something, then you're better off with plaintext than a false sense of security for your users.

	/r$

--  
Principal Security Engineer, Akamai Technologies
IM: rsalz@jabber.me Twitter: RichSalz

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