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 183D71BB for ; Mon, 4 Jul 2016 01:44:36 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.7.6 Received: from mail-oi0-f68.google.com (mail-oi0-f68.google.com [209.85.218.68]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 959FC1BC for ; Mon, 4 Jul 2016 01:44:31 +0000 (UTC) Received: by mail-oi0-f68.google.com with SMTP id w141so21175260oia.0 for ; Sun, 03 Jul 2016 18:44:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=btcc-com.20150623.gappssmtp.com; s=20150623; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=ddRJWKcYD3BPW291orsCyiY8gVOBzQ8un9pOmAkaTpg=; b=KNOqvI8DVmyGXppPGXkLdzByZ0P98kyPJPcIfSic8SeLshAQSPI//Cp1lIwEGBEbzT jhKLwyY2kChLbF0k4QZ7A9MfO76PNxJoI2yj27VC4UMXektqG6HGahpwPaHeVBN0fV6C oELsYRWi+kgKMOO0tK5FhaWVsCuXmneoFuV8TYtHPSxC0u4rGvoKMTsD5jOvgPt3HpVt tv4y2LGvOKKhELh0TFkxHe/yurO779PeZEENX6FSNcD2p/DwK1wrzSPunxH/uHtSAlFU tzkMjQyKWhIEgwDbZFVdeBElwdMgFw5onyjRQsmiIuKtqjcq/GxRZp+a/m8RWDzGLpls cmgQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=ddRJWKcYD3BPW291orsCyiY8gVOBzQ8un9pOmAkaTpg=; b=AEQYt+wjcW2z5q4wWb2a1wMI9qXzJdEhOL5dObOIp44Zzg/ob8Xin/V0V96PZtfPk6 I4jjKxcjqcgYdbuyEiIDXBoWMT+Zytf4iQyjnaP5D/rWNwZ9GeX9iRcjKqS8kBDtZ/1s PWQd3PjrEuHPxPaGsml6skB1mUCTvq2NNYsdautT0EI26gNPsm1NDFJ3WHAzmFCsmPZh DrDrRitBu0f9iur753xhpHNR8eeEqwM71c/iGPIpY0bu0qkjEMvOjzRcPxmvQqkbG47Z OtprQ3B7YjTS0PKa6aqflwRrxYcdqLhTlZykK47WL5ad1YVzcJBoUU5ANolJhhi4CsI0 HiSQ== X-Gm-Message-State: ALyK8tLen9eO4am7Qv/8M6e35Su5mpmuA2uzYLJF5pqSOnjAKWAVmFq/z/3OW4I3awJrOfBYJLS3B1Bz0nmEBEVJ X-Received: by 10.202.194.85 with SMTP id s82mr5558532oif.102.1467596670728; Sun, 03 Jul 2016 18:44:30 -0700 (PDT) MIME-Version: 1.0 Received: by 10.202.87.140 with HTTP; Sun, 3 Jul 2016 18:44:30 -0700 (PDT) In-Reply-To: References: <87h9cecad5.fsf@rustcorp.com.au> <577224E8.6070307@jonasschnelli.ch> <8760ssdd1u.fsf@rustcorp.com.au> <87oa6iavky.fsf@rustcorp.com.au> From: Arthur Chen Date: Mon, 4 Jul 2016 01:44:30 +0000 Message-ID: To: Zooko Wilcox , Bitcoin Protocol Discussion Content-Type: multipart/alternative; boundary=001a113db0983b9a820536c57a8b X-Spam-Status: No, score=-2.6 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HTML_MESSAGE,RCVD_IN_DNSWL_LOW autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.linux-foundation.org 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 01:44:36 -0000 --001a113db0983b9a820536c57a8b Content-Type: text/plain; charset=UTF-8 https://www.schneier.com/crypto-gram/archives/1998/1015.html#cipherdesign On Mon, Jul 4, 2016 at 1:23 AM, Arthur Chen wrote: > I strongly agree! > In crypto we should always follow well-studied open standard rather than > custom construction. > > On Fri, Jul 1, 2016 at 10:42 PM, Zooko Wilcox via bitcoin-dev < > bitcoin-dev@lists.linuxfoundation.org> wrote: > >> 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. >> >> https://eprint.iacr.org/2010/264 >> >> Also, of course, it is a great idea to re-use a standard >> (https://tools.ietf.org/html/rfc5869) and widely-understood crypto >> algorithm to reduce risk of both cryptographer errors and implementor >> errors. >> >> Of course, the cost of that is the you sometimes end up computing >> something that is a tiny bit more complicated or inefficient than a >> custom algorithm for our current use case. IMHO that's a cheap price >> to pay. >> >> Regards, >> >> Zooko >> _______________________________________________ >> bitcoin-dev mailing list >> bitcoin-dev@lists.linuxfoundation.org >> https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev >> > > > > -- > Xuesong (Arthur) Chen > Senior Principle Engineer > BlockChain Technologist > BTCC > -- Xuesong (Arthur) Chen Senior Principle Engineer BlockChain Technologist BTCC --001a113db0983b9a820536c57a8b Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable

On Mon, Jul 4, 2016 at 1:23 AM, Arthur Chen <art= hur.chen@btcc.com> wrote:
<= div dir=3D"ltr">
I strongly agree!
In crypto we should always = follow well-studied open standard rather than custom construction.

On Fri, Jul 1, 2016 at 10:42 PM, Zooko Wilcox via bitcoin-dev <bitcoin-dev@lists.linuxfoundation.org> wrote:=
I haven't been able to find the begi= nning of this thread, so apologies
if I've misunderstood what this is for, but it _sounds_ like we're<= br> re-inventing HKDF.

I'd recommend reading the paper about HKDF. It stands out among crypto<= br> 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.

https://eprint.iacr.org/2010/264

Also, of course, it is a great idea to re-use a standard
(https://tools.ietf.org/html/rfc5869) and widely-understood = crypto
algorithm to reduce risk of both cryptographer errors and implementor
errors.

Of course, the cost of that is the you sometimes end up computing
something that is a tiny bit more complicated or inefficient than a
custom algorithm for our current use case. IMHO that's a cheap price to pay.

Regards,

Zooko
_______________________________________________
bitcoin-dev mailing list
= bitcoin-dev@lists.linuxfoundation.org
https://lists.linuxfoundation.org/mail= man/listinfo/bitcoin-dev



--
= Xuesong (Arthur) Chen
Senior Principle Engineer
BlockChain Te= chnologist
BTCC



--
Xuesong (Arthur= ) Chen
Senior Principle Engineer
BlockChain Technologist
BTCC
--001a113db0983b9a820536c57a8b--