From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 1A0CE308 for ; Mon, 4 Jul 2016 06:37:51 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from server3 (server3.include7.ch [144.76.194.38]) by smtp1.linuxfoundation.org (Postfix) with ESMTP id 5877DF0 for ; Mon, 4 Jul 2016 06:37:50 +0000 (UTC) Received: by server3 (Postfix, from userid 115) id 13B552D002F7; Mon, 4 Jul 2016 08:37:49 +0200 (CEST) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.linux-foundation.org X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00, FSL_HELO_NON_FQDN_1 autolearn=ham version=3.3.1 Received: from Jonass-MacBook-Pro-2.local (cable-static-140-182.teleport.ch [87.102.140.182]) by server3 (Postfix) with ESMTPSA id 7DFF52D002F7 for ; Mon, 4 Jul 2016 08:37:48 +0200 (CEST) To: bitcoin-dev@lists.linuxfoundation.org References: <87h9cecad5.fsf@rustcorp.com.au> <577224E8.6070307@jonasschnelli.ch> <8760ssdd1u.fsf@rustcorp.com.au> <87oa6iavky.fsf@rustcorp.com.au> From: Jonas Schnelli Message-ID: <577A0439.5000506@jonasschnelli.ch> Date: Mon, 4 Jul 2016 08:37:45 +0200 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.11; rv:38.0) Gecko/20100101 Thunderbird/38.7.2 MIME-Version: 1.0 In-Reply-To: Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="RtHsO4uOF1X3c1LIi6gRU9ib8mnSxSeLv" Subject: Re: [bitcoin-dev] BIP 151 use of HMAC_SHA512 X-BeenThere: bitcoin-dev@lists.linuxfoundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Bitcoin Protocol Discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 04 Jul 2016 06:37:51 -0000 This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --RtHsO4uOF1X3c1LIi6gRU9ib8mnSxSeLv Content-Type: multipart/mixed; boundary="lxbg2tmm0vXDrM2sIQBitmqnVkFETeE93" From: Jonas Schnelli To: bitcoin-dev@lists.linuxfoundation.org Message-ID: <577A0439.5000506@jonasschnelli.ch> Subject: Re: [bitcoin-dev] BIP 151 use of HMAC_SHA512 References: <87h9cecad5.fsf@rustcorp.com.au> <577224E8.6070307@jonasschnelli.ch> <8760ssdd1u.fsf@rustcorp.com.au> <87oa6iavky.fsf@rustcorp.com.au> In-Reply-To: --lxbg2tmm0vXDrM2sIQBitmqnVkFETeE93 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable > I haven't been able to find the beginning of this thread, so apologies > if I've misunderstood what this is for, but it _sounds_ like we're > re-inventing HKDF. > I'd recommend reading the paper about HKDF. It stands out among crypto > papers for having a nice clear justification for each of its design > decisions, so you can see why they did it (very slightly) differently > than the various constructions proposed up-thread. Thanks Zooko I think HKDF instead of a single HMAC_SHA512 seams reasonable and something we should consider. I'll try to evaluate the implications of using HKDF over HMAC_SHA512 and will update the BIP if there are no concerns about it. --lxbg2tmm0vXDrM2sIQBitmqnVkFETeE93-- --RtHsO4uOF1X3c1LIi6gRU9ib8mnSxSeLv Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAEBCAAGBQJXegQ5AAoJECnUvLZBb1PsadYP/AtGE6LRj6eSrPa47hzzTig1 FkX+qQCom6HGAPnAMWs5cKwh7FlBaptF2aM5GcyhvcP7ZRNA0ib/Qe3i4mxl3DQ1 XCYAbReHKRcv1/Iui/jRoNozN9EliaWt9p36TVEYtJDAOOp9jUxRE683UiZl03nd SFYcnCsvmIERiTYSYYC8qHcvdzw2whfAt7f0vLDtoVH3ozFfFvbSOlYJs/FAdK22 RBaciE4g5vR4KqmHoO/vGot+2+TpaQ9I6qrVsKEIlIOlS3Y8iGn1UOx6YGNC5E25 MxY0DqAbMnUHM+nFXCGOhsc0zZw2AN7I/Y7BSQovQmycsTd3kp51H2IRY39xWCe4 yqvrH1BqueWiC4J91imQCgnNmV7MYEFApj/t4z5MAxJIgtrP6xVneeOuRRiuhoKa m4z82Mu15bQ8CaFhJnD8YC8ZcQPTn8UA00pNXBcACGtCSehSfFHxScMb3H6fgsus Jgrd4ToGykG6fuXlT2FlPBx6ixbBs9sSpveQEu0uuHDDw7cxCh8ifDyegv8fJQ9L holZb99BRgN1AwPOGSRdj/SW6E0+BGaHOZQEgZ9r/hkhoZDEUr9PKDjevUMAwSpY KDFGTEHO//xhsHrz5/KO6QMgypNorkeNie6hqETYvpNOrdo6MB9AleVj4IuVtHnG jiMxhXs6AaetAleOqWFn =YmIl -----END PGP SIGNATURE----- --RtHsO4uOF1X3c1LIi6gRU9ib8mnSxSeLv--