IETF Logo Mail Archive

Re: [TLS] What would make TLS cryptographically better for TLS 1.3

Robert Ransom <rransom.8774@gmail.com> Fri, 01 November 2013 21:34 UTC

Return-Path: <rransom.8774@gmail.com>
X-Original-To: tls@ietfa.amsl.com
Delivered-To: tls@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id D371711E8160 for <tls@ietfa.amsl.com>; Fri, 1 Nov 2013 14:34:49 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.6
X-Spam-Level:
X-Spam-Status: No, score=-2.6 tagged_above=-999 required=5 tests=[BAYES_00=-2.599, NO_RELAYS=-0.001]
Received: from mail.ietf.org ([12.22.58.30]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id EvWyl8XavyXd for <tls@ietfa.amsl.com>; Fri, 1 Nov 2013 14:34:49 -0700 (PDT)
Received: from mail-qa0-x234.google.com (mail-qa0-x234.google.com [IPv6:2607:f8b0:400d:c00::234]) by ietfa.amsl.com (Postfix) with ESMTP id 4C2D811E8143 for <tls@ietf.org>; Fri, 1 Nov 2013 14:34:49 -0700 (PDT)
Received: by mail-qa0-f52.google.com with SMTP id hu16so8343qab.18 for <tls@ietf.org>; Fri, 01 Nov 2013 14:34:48 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; bh=GJgNtNyzVIsV/QHenQHVzCrgWX4D/GzYK7Z0EWeaJDg=; b=v6/7fWleLEUteygh+iVR/UQYAmm2MN9VUzWotg2xeN3ZVDLH6YQrjoDPDRN9z/3veM i28w40mpSwA9vRJaTvhBblusAvWDkSe5DX7Rwywi6YrkMyi5/rud1Xou769ku3uSQJk2 MNoKUjdtMJIdlZrLdZb97MEUlrVWowXrj7dkDT/EA5UZP63zNROE62pf1p0n5zPoIN6g 74sg5q8JUGktts4cS6n80RMcDJ8TJOOt8gTCgwywL0Vs8Ov5QfV15Z2TmFPMeE0Sqa1F zxHc34E3jvbtXp3Wgl2/J0k+A6+8HRo++4we9z3rbvYoiI6Z+hD5UXXTCNfbiUVKCMgS 4v4Q==
MIME-Version: 1.0
X-Received: by 10.229.106.131 with SMTP id x3mr6783455qco.1.1383341688709; Fri, 01 Nov 2013 14:34:48 -0700 (PDT)
Received: by 10.229.12.198 with HTTP; Fri, 1 Nov 2013 14:34:48 -0700 (PDT)
In-Reply-To: <20131031230955.GB32733@gmail.com>
References: <CACsn0cnS7LWo+AN1maw-KYGhWXY1BLNPNOjiL-Y3UU3zG-Je_Q@mail.gmail.com> <20131031230955.GB32733@gmail.com>
Date: Fri, 01 Nov 2013 14:34:48 -0700
Message-ID: <CABqy+sof-NtSmZwTNN-x9Ekppz4PYMu2Pr3KjaEUdT7Wzxe7mQ@mail.gmail.com>
From: Robert Ransom <rransom.8774@gmail.com>
To: Nico Williams <nico@cryptonector.com>
Content-Type: text/plain; charset="UTF-8"
Cc: "tls@ietf.org" <tls@ietf.org>
Subject: Re: [TLS] What would make TLS cryptographically better for TLS 1.3
X-BeenThere: tls@ietf.org
X-Mailman-Version: 2.1.12
Precedence: list
List-Id: "This is the mailing list for the Transport Layer Security working group of the IETF." <tls.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/tls>, <mailto:tls-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/tls>
List-Post: <mailto:tls@ietf.org>
List-Help: <mailto:tls-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/tls>, <mailto:tls-request@ietf.org?subject=subscribe>
X-List-Received-Date: Fri, 01 Nov 2013 21:34:49 -0000

On 10/31/13, Nico Williams <nico@cryptonector.com> wrote:

>  - Many fewer nonce bytes and random IVs where possible.  Nonce payloads
>    should be sent when needed, if needed.  For example, to derive a
>    session key from an DHE shared secret one does not really need
>    nonces.  This means that counter modes are better, for example, than
>    CBC modes.

If the server sends a nonce during a DHE/ECDHE key exchange, the
server can safely reuse its DH keypair for multiple clients with no
further design or implementation considerations.  If the server does
not send a nonce, it must keep a replay-detection cache of client DH
public keys for the lifetime of its DH keypair.


Robert Ransom

v2.28.0 | Report a Bug | By Email | System Status