IETF Logo Mail Archive

Re: [openpgp] ECC point encoding and "flag byte"

Werner Koch <wk@gnupg.org> Thu, 04 March 2021 08:10 UTC

Return-Path: <wk@gnupg.org>
X-Original-To: openpgp@ietfa.amsl.com
Delivered-To: openpgp@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 1537D3A15B4 for <openpgp@ietfa.amsl.com>; Thu, 4 Mar 2021 00:10:14 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.099
X-Spam-Level:
X-Spam-Status: No, score=-2.099 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (1024-bit key) header.d=gnupg.org
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id NrBoRIbIm2uN for <openpgp@ietfa.amsl.com>; Thu, 4 Mar 2021 00:10:12 -0800 (PST)
Received: from kerckhoffs.g10code.com (kerckhoffs.g10code.com [IPv6:2001:aa8:fff1:100::22]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 3C1493A15B2 for <openpgp@ietf.org>; Thu, 4 Mar 2021 00:10:11 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=gnupg.org; s=20181017; h=Content-Type:MIME-Version:Message-ID:In-Reply-To:Date: References:Subject:Cc:To:From:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=TWHcKAq/LyYkpKGGPCw7yTRbKpu1YVmeL2Ufq4CttYE=; b=T/U0DspYS2U9m8ki47PLM6TLNd ROmlSIbExZ+QWaGtCn9ratNdkQVQZ4L4bJbhuuNHzTCvnsQyyIFX84qPGs+0bPwfQi34LYuLsWTy/ NXJrNcsxEG4+zCLtJgBsu9NGw7hk+CLvnVIDcXyDNa9VGTWfLT6AKPPIAxBoXesktmbg=;
Received: from uucp by kerckhoffs.g10code.com with local-rmail (Exim 4.89 #1 (Debian)) id 1lHj3f-0000sb-W3 for <openpgp@ietf.org>; Thu, 04 Mar 2021 09:10:08 +0100
Received: from wk by wheatstone.g10code.de with local (Exim 4.92 #5 (Debian)) id 1lHj2P-0006sq-3g; Thu, 04 Mar 2021 09:08:49 +0100
From: Werner Koch <wk@gnupg.org>
To: Ángel <angel@16bits.net>
Cc: openpgp@ietf.org
References: <87h7lyccns.fsf@fifthhorseman.net> <87czwj8d3b.fsf@wheatstone.g10code.de> <87v9a829z7.fsf@iwagami.gniibe.org> <e41505a7f57175dd18f45cf7c1e8c2f7ea63458d.camel@16bits.net>
Organisation: GnuPG e.V.
X-message-flag: Mails containing HTML will not be read! Please send only plain text.
Mail-Followup-To: Ángel <angel@16bits.net>, openpgp@ietf.org
Date: Thu, 04 Mar 2021 09:08:48 +0100
In-Reply-To: <e41505a7f57175dd18f45cf7c1e8c2f7ea63458d.camel@16bits.net> ("Ángel"'s message of "Wed, 03 Mar 2021 23:38:41 +0100")
Message-ID: <87v9a75oj3.fsf@wheatstone.g10code.de>
User-Agent: Gnus/5.13 (Gnus v5.13)
MIME-Version: 1.0
Content-Type: multipart/signed; boundary="=genetic_La_Familia_diwn_Blackbird_USP_S_Box_Flintlock_Indigo_Al_Qaed"; micalg="pgp-sha256"; protocol="application/pgp-signature"
Archived-At: <https://mailarchive.ietf.org/arch/msg/openpgp/UjTXgqPaw_OkDo77R7WmcR10jq4>
Subject: Re: [openpgp] ECC point encoding and "flag byte"
X-BeenThere: openpgp@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: "Ongoing discussion of OpenPGP issues." <openpgp.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/openpgp>, <mailto:openpgp-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/openpgp/>
List-Post: <mailto:openpgp@ietf.org>
List-Help: <mailto:openpgp-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/openpgp>, <mailto:openpgp-request@ietf.org?subject=subscribe>
X-List-Received-Date: Thu, 04 Mar 2021 08:10:14 -0000

On Wed,  3 Mar 2021 23:38, Ángel said:

>> In this situation, it's good to have a data element which can
>> represent **something in native format** (or anything, hopefully).
>
> No, you can't. Or rather, I expect it is an issue of terminology :-)

He meant in the algorithm/protocol/curve native format.  In fact we
already use the term "Native point format of the curve follows" in the
ECC pojnt compression flag bytes.

> On the other hand, if you mean an opaque blob private to the algorithm,
> that's perfectly fine (and what's already there, I think) *but* you
> need to define it anyway, it doesn't matter if it's in the OpenPGP spec

The algorithm/protocol/curve already defines this.


Shalom-Salam,

   Werner

-- 
Die Gedanken sind frei.  Ausnahmen regelt ein Bundesgesetz.

v2.23.0 | Report a Bug | By Email