Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id CBCD4BD4 for ; Thu, 22 Nov 2018 17:25:42 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.7.6 Received: from mail-ed1-f43.google.com (mail-ed1-f43.google.com [209.85.208.43]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id C11B7782 for ; Thu, 22 Nov 2018 17:25:41 +0000 (UTC) Received: by mail-ed1-f43.google.com with SMTP id b3so8323436ede.1 for ; Thu, 22 Nov 2018 09:25:41 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to; bh=ooOP+ETkN1TXkxjjSOXbd2dM1aTcYzmMpsgOH4ea0JE=; b=Wdx4NsQDLm7tSS4GyS9pq7y3eFG5HYVb7J90v6z7CCUSNd74Kjw6TvsfcKJxhhznVt QqvZDmlhYCMBOeT4zws582SKiQ3DLh4avSURpH0eoLy7vLS0pR/EV1/gCMLRIe1uyUIC CLy05yDeMt/92Bb7iStHMAhaURzAtUuxHgv3zmjRLN8sgTVaf7nZRhTC/sfuIS4y84Bt cSFXpgRvgDgugqMB8dtF0TNRASbdho4yTYvdXjqAqHtehihU57kF/hdnHC9Y5sEfIZNH HrCt/bcq0U1dgHUH9iVdDeZzwjqrcRv83YkPpoWjHmUfBVGQafDhvP8g8Bn/goTXvmLK wCFw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to; bh=ooOP+ETkN1TXkxjjSOXbd2dM1aTcYzmMpsgOH4ea0JE=; b=ATcs4ux6HJmF8U6fCOFxvAv9/IohlxwZeDvB4Epmm2ywVWXAa78qTaQCljEonT2EMs txcPTpNM/QtZpk8m8Urk/vuBnGaivBa2ngKTBv//N8PvXU1Y/Z6DGe2iLq43PSV2ufx3 OObIy+uZoxsPtWMR5t7AqWnl09LoVrTqkfPvkIWILsKRJ/f+ru/9uBykCHkD11ZCv0k8 CQSZhdNK375lWJxIyQZhISB8HSekEhZige+cdg2ITV0b5+bijvcqX0h02vAieCoI3SRt bwQ8i58YUfURbydYLD9N9wjpcZ99Atv/xxpcr5SxV8aPXxUrbPMFeEMnpTnxhvMmaAiS NM1A== X-Gm-Message-State: AGRZ1gLbI+D2M5U2DmbHE4bmMblcrNRQe2bUDvHakZl99t2kNs6qEteq siJX+/daJe2nFW8/r+GzOh/yuSU2TlqzgYlhwEmY13t+ju4= X-Google-Smtp-Source: AJdET5fJvrDn1J4CydZJOHIdCtg/q5cdacWm9ldKkVc4ZKtfLrNStjQNepdvPVbXYK2nBdipE5h/lXICJfbKkrgLoMo= X-Received: by 2002:a17:906:228d:: with SMTP id p13-v6mr8832371eja.159.1542907539925; Thu, 22 Nov 2018 09:25:39 -0800 (PST) MIME-Version: 1.0 References: In-Reply-To: From: Weiji Guo Date: Fri, 23 Nov 2018 01:25:07 +0800 Message-ID: To: bitcoin-dev@lists.linuxfoundation.org Content-Type: multipart/alternative; boundary="000000000000d6b126057b442709" X-Spam-Status: No, score=-2.0 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, FREEMAIL_FROM, HTML_MESSAGE, RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.linux-foundation.org X-Mailman-Approved-At: Fri, 23 Nov 2018 04:04:44 +0000 Subject: [bitcoin-dev] BIP- & SLIP-0039 -- better multi-language support 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, 22 Nov 2018 17:25:42 -0000 --000000000000d6b126057b442709 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Hi Everyone, Thank you very much in this thanks giving day for the detailed and well thought out responses. :) Steven Hatzakis via bitcoin-dev >: >* *Option 2*: Perhaps a revision is needed to how the BIP39 seed is *>* generated in the first place, such as by hashing the entropy instead of= the *>* words. Any thoughts on how viable that could be where the initial entro= py *>* is fed into the PBKDF2 function and not the words?* If we go this direction, I'd suggest that we pull Shamir's Secret Sharing into the game. Trezor's SLIP-0039 proposal is great and has many security aspects already covered. However, it does not allow any language other than English and Trezor team clearly stated that no other language will be supported. While I really want to keep the language independent design. So in the revision, I'd like to see a language id (allocated to each one having a defined wordlist) in the SSS share, as well as share id, threshold, index, share value, checksum etc. Regarding checksum scheme, SLIP-0039 proposals a 3-word Reed-Solomon design. It has a very good error checking capability but not very good at providing hints to error recovery. Trezor team opposes to the idea of providing hints to users regarding how to fix an error. This could lead to difficulties for some vendors, and in small probability, confusions to users (when there is a 2-word error) I do agree with Trezor team that it should be users' responsibility to recover from a detected error. However, there is a better way than solely rely on checksum. That is, as in our revision, we can support mnemonic in multiple languages simultaneously, why don't we use two languages, or one language + numbers to check each other? In Steven's example (language id, share id, etc. skipped) we could record a SSS share (assuming it is one of the shares just for the sake of example) like: >* *In English*: minimum fee sure ticket faculty banana gate purse caught *>* valley globe shift *>* *In Spanish*: mercado faja soledad tarea evadir aries gafas peine bu=CC= =81ho *>* tumor gerente reja* Or >* *In English*: minimum fee sure ticket faculty banana gate purse caught *>* valley globe shift* >* Word Indexes: 1128, 676, 1744, 1805, 653, 145, 770, 1396, 291, 1927, 794, 1582* Then software will have to check checksum as well as to check if words match each other. For example, "minimum"'s index value in English wordlist should equal to " *mercado*"'s in Spanish, or should equal to 1128. If any error is detected, combining the checksum value and dual-encoding information, it is much easier to figure out which word was handprinted incorrectly. BTW, it is very error prone to handprint. Some study suggests about 0.9% per word rate. See http://panko.shidler.hawaii.edu/HumanErr/Basic.htm Hotopf [1980] W sample (written exam). Per word 0.9% It is important to have an error recovery mechanism easy to understand and implement. Thanks, Weiji --000000000000d6b126057b442709 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Hi Everyone,

Thank you= very much in this thanks giving day for the detailed and well thought out = responses. :)

Steven Hatzakis via bitcoin-dev <bitcoin-dev at lists.l=
inuxfoundation.org>:
> *Option 2*: Perhaps a revision is needed to h=
ow the BIP39 seed is
> generated in the first place, such as by hashing the entropy in=
stead of the
> words. Any thoughts on how viable that could be where the initi=
al entropy
> is fed into the PBKDF2 function and not the words?
If = we go this direction, I'd suggest that we pull Shamir's Secret Shar= ing into the game. Trezor's=C2=A0
SLIP-0039 proposal is great= and has many security aspects already covered. However, it does=C2=A0
not allow any language other than English and Trezor team clearly sta= ted that no other language=C2=A0
will be supported.
While I really want to keep the language independent design. So= in the revision, I'd like to see=C2=A0
a language id (alloca= ted to each one having a defined wordlist) in the SSS share, as well as
share id, threshold, index, share value, checksum etc.=C2=A0

Regarding checksum scheme, SLIP-0039 proposals a 3-word R= eed-Solomon design. It has a very
good error checking capability = but not very good at providing hints to error recovery. Trezor team=C2=A0
opposes to the idea of providing hints to users regarding how to f= ix an error. This could lead to
difficulties for some vendors, an= d in small probability, confusions to users (when there is a 2-word
error)

I do agree with Trezor team that it shou= ld be users' responsibility to recover from a detected error.
However, there is a better way than solely rely on checksum. That is, as i= n our revision, we can=C2=A0
support mnemonic in multiple languag= es simultaneously, why don't we use two languages, or one=C2=A0
language=C2=A0+ numbers to check each other? In Steven's example (la= nguage id, share id, etc. skipped)=C2=A0
we could record a SSS sh= are (assuming it is one of the shares just for the sake of example) like:

>=
; *In English*: minimum fee sure ticket faculty banana gate purse caught
> valley globe shift
> *In Spanish*: mercado faja soledad tarea evadir aries gafas pei=
ne bu=CC=81ho
> tumor gerente reja
Or

> *In Englis=
h*: minimum fee sure ticket faculty banana gate purse caught
> valley globe shift
> Word Indexes: 1128, 676, 1744, 1805, 653, 145, 770, 13=
96, 291, 1927, 794, 1582

Then software will have to check checksum as wel=
l as to check if words match each other. For=C2=A0
example, "=
;minimum"'s index value in English wordlist should equal to "=
mercado"'s =
in Spanish,
or should equal to 1128.=C2=A0

If any error is detected, combining the checksum value and dual-encoding=
 information, it is much
easier to figure out which word was hand=
printed incorrectly.=C2=A0

BTW, it is very error p=
rone to handprint. Some study suggests about 0.9% per word rate. See
<=
div>http://p=
anko.shidler.hawaii.edu/HumanErr/Basic.htm
=

Hoto=
pf [1980]
W sample (written exam). Per word
0.9%

It is=
 important to have an error recovery mechanism easy to understand and imple=
ment.=C2=A0

Thanks,
Weiji


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