Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 646165A9 for ; Thu, 27 Jul 2017 18:56:46 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.7.6 Received: from mail-yw0-f179.google.com (mail-yw0-f179.google.com [209.85.161.179]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 689CE3CA for ; Thu, 27 Jul 2017 18:56:45 +0000 (UTC) Received: by mail-yw0-f179.google.com with SMTP id u207so50337641ywc.3 for ; Thu, 27 Jul 2017 11:56:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:from:date:message-id:subject:to; bh=P0WDxnmDHPfYed/c8pGxv30Bx/r/Yx3NfxTKETu1sOM=; b=P65QwRBDt3YitoWtSUFYtnamKh/j3cSrIV2Dzcz/X6zC1Xs7xnKju/xdG2ClIH9wqv QjBKh98WTBH4x0pecxuY2eCBOniwwEGu7DLoj3zBgcUlN/5uTijc/PPER6Mzgxhny2nt pRYP/BhL8IQqSZ3+qAfKpZoEty3C03T/tY97D8jqkz1fXHl2xeoVc/O0tGyfq+tIjG4Y VvuE0QAz4RZe69phHAQgkD1hTT/EXr2oj3V3lO7JhEk9Zz/uKqbdl/DWF1u30O7O6EWh cEkRXNvbZWy4bUeT628qAChWLcc10Ko8MxToMSf4lHx+HZqjhHwYtjzCr6GROGK4oeXw QDqg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:from:date:message-id:subject:to; bh=P0WDxnmDHPfYed/c8pGxv30Bx/r/Yx3NfxTKETu1sOM=; b=nUM2vAKT0d6L/UxfCk3ElUlQUpqViv1fNwVOM8TQIJUV612f4OifmxqU0Qq0Btz5xb 6qzFgN3zDtYxWGXxmALEzRnykz91jCYa8liRMI2K2SCd2slGgkSkhoc+WAC3OsqQ3lVN T+lZgR2ByK4Tw+3p6D5+KDG3SqCwlzbBinShX3aLHEQBYgOl7kgFiaMVJz1fjKbGq/vg nvA0Rgr8HHKbSzWOOLAbTOfXG+si+N8gherl7gHliNaIBPSKnZJzgJ/tRzeIxfJyynDd iXXvwUCKm1Rf12C3lz6vVzvrUqH4khzOZTrdNx+LzgkxLki5fqsChY7Y0kyX32EGsAf/ ovEA== X-Gm-Message-State: AIVw110DNWIWFKVpN/xjMT95q/kR0jPAwLiTTzJFOgnd+pZUdAJG4gbQ 3C3VegNm+xB4ntHJqM7d9F7Ugq5tTN3r X-Received: by 10.37.119.81 with SMTP id s78mr4398547ybc.33.1501181804111; Thu, 27 Jul 2017 11:56:44 -0700 (PDT) MIME-Version: 1.0 Received: by 10.129.226.67 with HTTP; Thu, 27 Jul 2017 11:56:43 -0700 (PDT) From: Bryan Bishop Date: Thu, 27 Jul 2017 13:56:43 -0500 Message-ID: To: Bitcoin Dev , Bryan Bishop Content-Type: multipart/alternative; boundary="001a114bd8522d714e055551206b" X-Spam-Status: No, score=-1.5 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, FREEMAIL_FROM, HTML_MESSAGE, RCVD_IN_DNSWL_NONE, RCVD_IN_SORBS_SPAM autolearn=no version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.linux-foundation.org Subject: [bitcoin-dev] Fwd: [Mimblewimble] proofs of position and UTXO set commitments 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: Thu, 27 Jul 2017 18:56:46 -0000 --001a114bd8522d714e055551206b Content-Type: text/plain; charset="UTF-8" ---------- Forwarded message ---------- From: Bram Cohen Date: Thu, Jul 27, 2017 at 1:21 PM Subject: Re: [Mimblewimble] Switch to Blake2 To: Ignotus Peverell Cc: Bryan Bishop I have quite a few thoughts about proofs of position. I gave a talk about it which hopefully gets the points across if you go through all the Q&A: https://www.youtube.com/watch?v=52FVkHlCh7Y On Mon, Jul 24, 2017 at 12:12 PM, Ignotus Peverell < igno.peverell@protonmail.com> wrote: > Interesting, thanks for the link. Seems we arrived at similar conclusions > regarding the hash function, with similar frustrations with respect to > blake2b/2s. > > Funny that it's also for the same merkle set application. We ended up with > a Merkle Mountain Range [1] instead of a Patricia tree. The MMR is > append-only and makes pruning easy, which works well for MimbleWimble. You > can navigate down the MMR with just the position the element was inserted > at, so we just keep a simple index for that. Memory layout is great as a > lot of it is immutable and sit close together, although the current impl > doesn't leverage that too well yet. Wonder if Bram looked at MMRs? Patricia > trees may make more sense for Bitcoin though. > > Proof of positions are cool, might look at that some more in the near > future, when we're less busy implementing everything else ;-) > > > - Igno > > [1] https://github.com/ignopeverell/grin/blob/master/doc/merkle.md > > -------- Original Message -------- > Subject: Re: [Mimblewimble] Switch to Blake2 > Local Time: July 24, 2017 6:44 PM > UTC Time: July 24, 2017 6:44 PM > From: kanzure@gmail.com > To: Ignotus Peverell , Bram Cohen < > bram@bittorrent.com>, Bryan Bishop > > On Fri, Jul 21, 2017 at 1:12 PM, Ignotus Peverell < > igno.peverell@protonmail.com> wrote: > >> So I'm considering a switch to the Blake2 [3] hash function. >> > > Bram recently made some comments about blake a few weeks ago: > http://diyhpl.us/wiki/transcripts/sf-bitcoin-meetup/2017-07- > 08-bram-cohen-merkle-sets/ > > - Bryan > http://heybryan.org/ > 1 512 203 0507 <(512)%20203-0507> > > > -- - Bryan http://heybryan.org/ 1 512 203 0507 --001a114bd8522d714e055551206b Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable

---------- Forwarded messag= e ----------
From: Bram Cohen <bram@bittorrent.com>
Date: Thu, Jul 27, 2017 at 1:21 PM
Subject: Re: [Mimblew= imble] Switch to Blake2
To: Ignotus Peverell <igno.peverell@protonmail.com>
Cc: Bryan = Bishop <kanzure@gmail.com>

I have quite a few thoughts about proofs of posi= tion. I gave a talk about it which hopefully gets the points across if you = go through all the Q&A:


On Mon, J= ul 24, 2017 at 12:12 PM, Ignotus Peverell <igno.peverell@proton= mail.com> wrote:
Int= eresting, thanks for the link. Seems we arrived at similar conclusions rega= rding the hash function, with similar frustrations with respect to blake2b/= 2s.

Funny that it's also for the same merk= le set application. We ended up with a Merkle Mountain Range [1] instead of= a Patricia tree. The MMR is append-only and makes pruning easy, which work= s well for MimbleWimble. You can navigate down the MMR with just the positi= on the element was inserted at, so we just keep a simple index for that. Me= mory layout is great as a lot of it is immutable and sit close together, al= though the current impl doesn't leverage that too well yet. Wonder if B= ram looked at MMRs? Patricia trees may make more sense for Bitcoin though.<= br>

Proof of positions are cool, might look at tha= t some more in the near future, when we're less busy implementing every= thing else ;-)


=
- Igno

https://github.com/ignopeverell/grin/blob/mast= er/doc/merkle.md

-------- Original Message --------
Subject: R= e: [Mimblewimble] Switch to Blake2
Local Time: July 24, 2017 = 6:44 PM
UTC Time: July 24, 2017 6:44 PM
From: <= a href=3D"mailto:kanzure@gmail.com" target=3D"_blank">kanzure@gmail.com=
To: Ignotus Peverell <igno.peverell@protonmail.com>, B= ram Cohen <bram= @bittorrent.com>, Bryan Bishop <kanzure@gmail.com>

On= Fri, Jul 21, 2017 at 1:12 PM, Ignotus Peverell <igno.peverell@protonmail.com> wrote:
So I'm c= onsidering a switch to the Blake2 [3] hash function.
=

Bram recently made some comments about blake a fe= w weeks ago:

- Bryan
=


=



--
- Bryan
http://heybryan.org/
1 512 2= 03 0507
--001a114bd8522d714e055551206b--