Date: Thu, 12 Mar 2015 04:21:59 +0000 (UTC)
From: Thy Shizzle <thashiznets@yahoo.com.au>
To: "neillm@thecodefactory.org" <neillm@thecodefactory.org>
Message-ID: <692694585.4537988.1426134119107.JavaMail.yahoo@mail.yahoo.com>
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Cc: "Bitcoin-development@lists.sourceforge.net"
	<Bitcoin-development@lists.sourceforge.net>
Subject: Re: [Bitcoin-development] Electrum 2.0 has been tagged
Precedence: list
Reply-To: Thy Shizzle <thashiznets@yahoo.com.au>

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=C2=A0"I agree that it's true that a static wordlist is
 required once people have started using BIP39 for anything real and
 changing the word lists will invalidate any existing mnemonics"
^ This is incorrect I think Neill, the reason is that the only thing that h=
appens when you change the wordlist is that entropy points to different wor=
ds. But remember, entropy is disposed. Yes in my code I allow for the keepi=
ng of entropy etc, it also lets me "hot swap" between different language wo=
rdlists etc but in real world implementation the entropy is forgotten and n=
ot stored. So changing the wordlist merely allows new mnemonic phrases to b=
e generated but it has a nil impact on previously generated mnemonics UNLES=
S you are trying to rebuild from entropy but you wouldn't do that. You woul=
d be rebuilding from the Mnemonic in real world scenario. You really can ha=
ve a word list of total rubbish in BIP39 as long as it is 2048 words long t=
hat is all! If you input the mnemonic made out of rubbish words so for e.g =
"uyuy jkjasd sdsd sdsdd yuuyu sdsds iooioi sdasds uyuyuy sdsdsd tyyty rwetr=
tr" and no matter what BIP39 implementation you put it in, it will always g=
enerate the same seed bytes thus allowing for complete and universal seed d=
erivation without any reliance on word list. The word list is merely to gen=
erate a mnemonic, after that it has no role in seed generation so you can c=
hange it at anytime and it will never effect future mnemonics.

On Thu, Mar 12, 2015 at 02:16:38AM +0000, Thy Shizzle wrote:
> That's disappointing the Electrum 2.0 doesn't use BIP39.

Agreed, but I don't know the full background on this.

> Changing the wordlist in the future has ZERO effect on derived seed, what=
ever mnemonic you provide will always generate the same seed, BIP39 is not =
mapping the words back to numbers etc to derive seed.

That's true for generating new mnemonics (i.e. same entropy can
generate any combinations of words), but not for converting a mnemonic
to a seed (i.e. a specific wordlist/passphrase should always generate
the same seed).=C2=A0 I agree that it's true that a static wordlist is
required once people have started using BIP39 for anything real and
changing the word lists will invalidate any existing mnemonics (unless
your 'new' wordlist simply substitutes one word for another and the
index mapping is made public ... which means it's not really an
arbitrary word list).

> Version is something that can be dealt with after the fact, hopefully sta=
ndardised (curious why didn't you work with the BIP39 to insert version ins=
tead of do something different to BIP39?)
> So most of what you are suggesting as problems are not.

I don't see how this can work given the BIP39 spec as it is today
(there's simply no room for a version in the bits).=C2=A0 I do think
versioning would be nice, but as of now, I'm in the camp that thinks
complete wallet interoperability is a bit of a myth -- so long as you
can fundamentally move into/out of wallets at will.

-Neill.

> As for the common words between languages, I have discussed this with the=
 provider of the Chinese wordlists as they shared some words between simpli=
fied and traditional, but I found it easy to look for a word in the mnemoni=
c that is unique to that language/wordlist and so straight away you can det=
ermine the language, remembering you get minimum 12 goes at doing that :)
> Also then I asked myself, do we really care about detecting the language?=
 Probably not because we don't need to use the wordlist ever again after cr=
eation, we literally accept the mnemonic, normalise it then hash it into a =
seed. From what I'm reading, Electrum 2.0 really should have BIP39, it woul=
d take almost no effort to put it in and I think you should do that :) I do=
n't have any interest in BIP39 other than it being a standard. I think TREZ=
OR may have an interest in it?
> Thomas V:
> "Thanks Mike, and sorry to answer a bit late; it has been a busy couple
> of weeks.
>=20
> You are correct, a BIP39 seed phrase will not work in Electrum, and vice
> versa. It is indeed unfortunate. However, I believe BIP39 should not be
> followed, because it reproduces two mistakes I did when I designed the
> older Electrum seed system. Let me explain.
>=20
> The first problem I have with BIP39 is that the seed phrase does not
> include a version number.
>=20
> Wallet development is still in an exploratory phase, and we should
> expect even more innovation in this domain. In this context, it is
> unwise to make decisions that prevent future innovation.
>=20
> However, when we give a seed phrase to users, we have a moral obligation
> to keep supporting this seed phrase in future versions. We cannot simply
> announce to Electrum users that their old seed phrase is not supported
> anymore, because we created a new version of the software that uses a
> different derivation. This could lead to financial losses for users who
> are unaware of these technicalities. Well, at least, that is how I feel
> about it.
>=20
> BIP39 and Electrum v2 have a very different ways of handling future
> innovation. Electrum v2 seed phrases include an explicit version number,
> that indicates how the wallet addresses should be derived. In contrast,
> BIP39 seed phrases do not include a version number at all. BIP39 is
> meant to be combined with BIP43, which stipulates that the wallet
> structure should depend on the BIP32 derivation path used for the wallet
> (although BIP43 is not followed by all BIP39 compatible wallets). Thus,
> innovation in BIP43 is allowed only within the framework of BIP32. In
> addition, having to explore the branches of the BIP32 tree in order to
> determine the type of wallet attached to a seed might be somewhat
> inefficient.
>=20
> The second problem I see with BIP39 is that it requires a fixed
> wordlist. Of course, this forbids innovation in the wordlist itself, but
> that's not the main problem. When you write a new standard, it is
> important to keep this standard minimal, given the goal you want to
> achieve. I believe BIP39 could (and should) have been written without
> including the wordlist in the standard.
>=20
> There are two ways to derive a master key from a mnemonic phrase:
> =C2=A01. A bidirectional mapping between words and numbers, as in old
> Electrum versions. Pros: bidirectional means that you can do Shamir
> secret sharing of your seed. Cons: It requires a fixed wordlist.
> =C2=A02. Use a hash of the seed phrase (pbkdf). Pros: a fixed wordlist is=
 not
> required. Cons: the mapping isn't bidirectional.
>=20
> Electrum v1 uses (1). Electrum v2 uses (2).
>=20
> Early versions of BIP39 used (1), and later they switched to (2).
> However, BIP39 uses (2) only in order to derive the wallet keys, not for
> its checksum. The BIP39 checksum uses (1), and it does requires a fixed
> wordlist. This is just plainly inconsistent. As a result, you have
> neither wordlist flexibility, nor Shamir secret sharing.
>=20
> Having a fixed wordlist is very unfortunate. First, it means that BIP39
> will probably never leave the 'draft' stage, until all languages of the
> world have been added. Second, once you add a wordlist for a new
> language, you cannot change it anymore, because it will break existing
> seed phrases; therefore you have to be extremely careful in the way you
> design these wordlists. Third, languages often have words in common.
> When you add a new language to the list, you should not use words
> already used by existing wordlists, in order to ensure that the language
> can be detected. It leads to a first come first served situation, that
> might not be sustainable in the future.
>=20
> In order to support the old Electrum v1 seeds, all future versions of
> Electrum will have to include the old wordlist. In addition, when
> generating new seed phrases, Electrum now has to avoid collisions with
> old seed phrases, because the old ones did not have a version number.
> This is painful enough, I will not repeat the same errors twice.
>=20
> Electrum v2 derives both its private keys and its checksum/version
> number using a hash of the seed phrase. This means that wordlists can be
> added and modified in the future, without breaking existing seed
> phrases. It also means that it will be very easy for other wallets to
> support Electrum seedphrases: it requires about 20 lines of code, and no
> wordlist is required."
>=20
>=20
> Thomas
>=20
>=20
> Le 02/03/2015 16:37, Mike Hearn a =C3=A9crit :
> > Congrats Thomas! Glad to see Electrum 2 finally launch.
> >=20
> >=20
> >> * New seed derivation method (not compatible with BIP39).
> >=20
> >=20
> > Does this mean a "12 words" wallet created by Electrum won't work if
> > imported into some other wallet that supports BIP39? Vice versa? This s=
eems
> > unfortunate. I guess if seeds are being represented with 12 words
> > consistently, people will expect them to work everywhere.
> >=20
>=20
> -------------------------------------------------------------------------=
-----
> Dive into the World of Parallel Programming The Go Parallel Website, spon=
sored
> by Intel and developed in partnership with Slashdot Media, is your hub fo=
r all
> things parallel software development, from weekly thought leadership blog=
s to
> news, videos, case studies, tutorials and more. Take a look and join the=
=20
> conversation now. http://goparallel.sourceforge.net/
> _______________________________________________
> Bitcoin-development mailing list
> Bitcoin-development@lists.sourceforge.net
> Bitcoin-development --
> | =C2=A0 |
> | =C2=A0 | =C2=A0 | =C2=A0 | =C2=A0 | =C2=A0 |
> | Bitcoin-development --To see the collection of prior postings to the li=
st, visit the Bitcoin-development Archives. |
> |=C2=A0 |
> | View on lists.sourceforge.net | Preview by Yahoo |
> |=C2=A0 |
> | =C2=A0 |
>=20
>=C2=A0 =C2=A0
>=20
>=C2=A0=20
>=C2=A0=C2=A0=C2=A0=20

> -------------------------------------------------------------------------=
-----
> Dive into the World of Parallel Programming The Go Parallel Website, spon=
sored
> by Intel and developed in partnership with Slashdot Media, is your hub fo=
r all
> things parallel software development, from weekly thought leadership blog=
s to
> news, videos, case studies, tutorials and more. Take a look and join the=
=20
> conversation now. http://goparallel.sourceforge.net/

> _______________________________________________
> Bitcoin-development mailing list
> Bitcoin-development@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/bitcoin-development

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<html><body><div style=3D"color:#000; background-color:#fff; font-family:He=
lvetica Neue-Light, Helvetica Neue Light, Helvetica Neue, Helvetica, Arial,=
 Lucida Grande, Sans-Serif;font-size:16px"><div id=3D"yui_3_16_0_1_14261226=
60566_28256">&nbsp;"I agree that it's true that a static wordlist is<br> re=
quired once people have started using BIP39 for anything real and<br> chang=
ing the word lists will invalidate any existing mnemonics"</div><div id=3D"=
yui_3_16_0_1_1426122660566_28554"><br></div><div id=3D"yui_3_16_0_1_1426122=
660566_28553" dir=3D"ltr">^ This is incorrect I think Neill, the reason is =
that the only thing that happens when you change the wordlist is that entro=
py points to different words. But remember, entropy is disposed. Yes in my =
code I allow for the keeping of entropy etc, it also lets me "hot swap" bet=
ween different language wordlists etc but in real world implementation the =
entropy is forgotten and not stored. So changing the wordlist merely allows=
 new mnemonic phrases to be generated but it has a nil impact on previously=
 generated mnemonics UNLESS you are trying to rebuild from entropy but you =
wouldn't do that. You would be rebuilding from the Mnemonic in real world s=
cenario. You really can have a word list of total rubbish in BIP39 as long =
as it is 2048 words long that is all! If you input the mnemonic made out of=
 rubbish words so for e.g "uyuy jkjasd sdsd sdsdd yuuyu sdsds iooioi sdasds=
 uyuyuy sdsdsd tyyty rwetrtr" and no matter what BIP39 implementation you p=
ut it in, it will always generate the same seed bytes thus allowing for com=
plete and universal seed derivation without any reliance on word list. The =
word list is merely to generate a mnemonic, after that it has no role in se=
ed generation so you can change it at anytime and it will never effect futu=
re mnemonics.</div><div id=3D"yui_3_16_0_1_1426122660566_28581" dir=3D"ltr"=
><br></div><div id=3D"yui_3_16_0_1_1426122660566_28255"><br></div><div id=
=3D"yui_3_16_0_1_1426122660566_28254">On Thu, Mar 12, 2015 at 02:16:38AM +0=
000, Thy Shizzle wrote:<br>
&gt; That's disappointing the Electrum 2.0 doesn't use BIP39.<br>
<br>
Agreed, but I don't know the full background on this.<br>
<br>
&gt; Changing the wordlist in the future has ZERO effect on derived seed, w=
hatever mnemonic you provide will always generate the same seed, BIP39 is n=
ot mapping the words back to numbers etc to derive seed.<br>
<br>
That's true for generating new mnemonics (i.e. same entropy can<br>
generate any combinations of words), but not for converting a mnemonic<br>
to a seed (i.e. a specific wordlist/passphrase should always generate<br>
the same seed).&nbsp; I agree that it's true that a static wordlist is<br>
required once people have started using BIP39 for anything real and<br>
changing the word lists will invalidate any existing mnemonics (unless<br>
your 'new' wordlist simply substitutes one word for another and the<br>
index mapping is made public ... which means it's not really an<br>
arbitrary word list).<br>
<br>
&gt; Version is something that can be dealt with after the fact, hopefully =
standardised (curious why didn't you work with the BIP39 to insert version =
instead of do something different to BIP39?)<br>
&gt; So most of what you are suggesting as problems are not.<br>
<br>
I don't see how this can work given the BIP39 spec as it is today<br>
(there's simply no room for a version in the bits).&nbsp; I do think<br>
versioning would be nice, but as of now, I'm in the camp that thinks<br>
complete wallet interoperability is a bit of a myth -- so long as you<br>
can fundamentally move into/out of wallets at will.<br>
<br>
-Neill.<br>
<br>
&gt; As for the common words between languages, I have discussed this with =
the provider of the Chinese wordlists as they shared some words between sim=
plified and traditional, but I found it easy to look for a word in the mnem=
onic that is unique to that language/wordlist and so straight away you can =
determine the language, remembering you get minimum 12 goes at doing that :=
)<br>
&gt; Also then I asked myself, do we really care about detecting the langua=
ge? Probably not because we don't need to use the wordlist ever again after=
 creation, we literally accept the mnemonic, normalise it then hash it into=
 a seed. From what I'm reading, Electrum 2.0 really should have BIP39, it w=
ould take almost no effort to put it in and I think you should do that :) I=
 don't have any interest in BIP39 other than it being a standard. I think T=
REZOR may have an interest in it?<br>
&gt; Thomas V:<br>
&gt; "Thanks Mike, and sorry to answer a bit late; it has been a busy coupl=
e<br>
&gt; of weeks.<br>
&gt; <br>
&gt; You are correct, a BIP39 seed phrase will not work in Electrum, and vi=
ce<br>
&gt; versa. It is indeed unfortunate. However, I believe BIP39 should not b=
e<br>
&gt; followed, because it reproduces two mistakes I did when I designed the=
<br>
&gt; older Electrum seed system. Let me explain.<br>
&gt; <br>
&gt; The first problem I have with BIP39 is that the seed phrase does not<b=
r>
&gt; include a version number.<br>
&gt; <br>
&gt; Wallet development is still in an exploratory phase, and we should<br>
&gt; expect even more innovation in this domain. In this context, it is<br>
&gt; unwise to make decisions that prevent future innovation.<br>
&gt; <br>
&gt; However, when we give a seed phrase to users, we have a moral obligati=
on<br>
&gt; to keep supporting this seed phrase in future versions. We cannot simp=
ly<br>
&gt; announce to Electrum users that their old seed phrase is not supported=
<br>
&gt; anymore, because we created a new version of the software that uses a<=
br>
&gt; different derivation. This could lead to financial losses for users wh=
o<br>
&gt; are unaware of these technicalities. Well, at least, that is how I fee=
l<br>
&gt; about it.<br>
&gt; <br>
&gt; BIP39 and Electrum v2 have a very different ways of handling future<br=
>
&gt; innovation. Electrum v2 seed phrases include an explicit version numbe=
r,<br>
&gt; that indicates how the wallet addresses should be derived. In contrast=
,<br>
&gt; BIP39 seed phrases do not include a version number at all. BIP39 is<br=
>
&gt; meant to be combined with BIP43, which stipulates that the wallet<br>
&gt; structure should depend on the BIP32 derivation path used for the wall=
et<br>
&gt; (although BIP43 is not followed by all BIP39 compatible wallets). Thus=
,<br>
&gt; innovation in BIP43 is allowed only within the framework of BIP32. In<=
br>
&gt; addition, having to explore the branches of the BIP32 tree in order to=
<br>
&gt; determine the type of wallet attached to a seed might be somewhat<br>
&gt; inefficient.<br>
&gt; <br>
&gt; The second problem I see with BIP39 is that it requires a fixed<br>
&gt; wordlist. Of course, this forbids innovation in the wordlist itself, b=
ut<br>
&gt; that's not the main problem. When you write a new standard, it is<br>
&gt; important to keep this standard minimal, given the goal you want to<br=
>
&gt; achieve. I believe BIP39 could (and should) have been written without<=
br>
&gt; including the wordlist in the standard.<br>
&gt; <br>
&gt; There are two ways to derive a master key from a mnemonic phrase:<br>
&gt; &nbsp;1. A bidirectional mapping between words and numbers, as in old<=
br>
&gt; Electrum versions. Pros: bidirectional means that you can do Shamir<br=
>
&gt; secret sharing of your seed. Cons: It requires a fixed wordlist.<br>
&gt; &nbsp;2. Use a hash of the seed phrase (pbkdf). Pros: a fixed wordlist=
 is not<br>
&gt; required. Cons: the mapping isn't bidirectional.<br>
&gt; <br>
&gt; Electrum v1 uses (1). Electrum v2 uses (2).<br>
&gt; <br>
&gt; Early versions of BIP39 used (1), and later they switched to (2).<br>
&gt; However, BIP39 uses (2) only in order to derive the wallet keys, not f=
or<br>
&gt; its checksum. The BIP39 checksum uses (1), and it does requires a fixe=
d<br>
&gt; wordlist. This is just plainly inconsistent. As a result, you have<br>
&gt; neither wordlist flexibility, nor Shamir secret sharing.<br>
&gt; <br>
&gt; Having a fixed wordlist is very unfortunate. First, it means that BIP3=
9<br>
&gt; will probably never leave the 'draft' stage, until all languages of th=
e<br>
&gt; world have been added. Second, once you add a wordlist for a new<br>
&gt; language, you cannot change it anymore, because it will break existing=
<br>
&gt; seed phrases; therefore you have to be extremely careful in the way yo=
u<br>
&gt; design these wordlists. Third, languages often have words in common.<b=
r>
&gt; When you add a new language to the list, you should not use words<br>
&gt; already used by existing wordlists, in order to ensure that the langua=
ge<br>
&gt; can be detected. It leads to a first come first served situation, that=
<br>
&gt; might not be sustainable in the future.<br>
&gt; <br>
&gt; In order to support the old Electrum v1 seeds, all future versions of<=
br>
&gt; Electrum will have to include the old wordlist. In addition, when<br>
&gt; generating new seed phrases, Electrum now has to avoid collisions with=
<br>
&gt; old seed phrases, because the old ones did not have a version number.<=
br>
&gt; This is painful enough, I will not repeat the same errors twice.<br>
&gt; <br>
&gt; Electrum v2 derives both its private keys and its checksum/version<br>
&gt; number using a hash of the seed phrase. This means that wordlists can =
be<br>
&gt; added and modified in the future, without breaking existing seed<br>
&gt; phrases. It also means that it will be very easy for other wallets to<=
br>
&gt; support Electrum seedphrases: it requires about 20 lines of code, and =
no<br>
&gt; wordlist is required."<br>
&gt; <br>
&gt; <br>
&gt; Thomas<br>
&gt; <br>
&gt; <br>
&gt; Le 02/03/2015 16:37, Mike Hearn a =C3=A9crit :<br>
&gt; &gt; Congrats Thomas! Glad to see Electrum 2 finally launch.<br>
&gt; &gt; <br>
&gt; &gt; <br>
&gt; &gt;&gt; * New seed derivation method (not compatible with BIP39).<br>
&gt; &gt; <br>
&gt; &gt; <br>
&gt; &gt; Does this mean a "12 words" wallet created by Electrum won't work=
 if<br>
&gt; &gt; imported into some other wallet that supports BIP39? Vice versa? =
This seems<br>
&gt; &gt; unfortunate. I guess if seeds are being represented with 12 words=
<br>
&gt; &gt; consistently, people will expect them to work everywhere.<br>
&gt; &gt; <br>
&gt; <br>
&gt; ----------------------------------------------------------------------=
--------<br>
&gt; Dive into the World of Parallel Programming The Go Parallel Website, s=
ponsored<br>
&gt; by Intel and developed in partnership with Slashdot Media, is your hub=
 for all<br>
&gt; things parallel software development, from weekly thought leadership b=
logs to<br>
&gt; news, videos, case studies, tutorials and more. Take a look and join t=
he <br>
&gt; conversation now. <a tabindex=3D"-1" href=3D"http://goparallel.sourcef=
orge.net/" target=3D"_parent"><font color=3D"#0066cc">http://goparallel.sou=
rceforge.net/</font></a><br>
&gt; _______________________________________________<br>
&gt; Bitcoin-development mailing list<br>
&gt; Bitcoin-development@lists.sourceforge.net<br>
&gt; Bitcoin-development --<br>
&gt; | &nbsp; |<br>
&gt; | &nbsp; | &nbsp; | &nbsp; | &nbsp; | &nbsp; |<br>
&gt; | Bitcoin-development --To see the collection of prior postings to the=
 list, visit the Bitcoin-development Archives. |<br>
&gt; |&nbsp; |<br>
&gt; | View on lists.sourceforge.net | Preview by Yahoo |<br>
&gt; |&nbsp; |<br>
&gt; | &nbsp; |<br>
&gt; <br>
&gt;&nbsp; &nbsp;<br>
&gt; <br>
&gt;&nbsp; <br>
&gt;&nbsp;&nbsp;&nbsp; <br>
<br>
&gt; ----------------------------------------------------------------------=
--------<br>
&gt; Dive into the World of Parallel Programming The Go Parallel Website, s=
ponsored<br>
&gt; by Intel and developed in partnership with Slashdot Media, is your hub=
 for all<br>
&gt; things parallel software development, from weekly thought leadership b=
logs to<br>
&gt; news, videos, case studies, tutorials and more. Take a look and join t=
he <br>
&gt; conversation now. <a tabindex=3D"-1" href=3D"http://goparallel.sourcef=
orge.net/" target=3D"_parent"><font color=3D"#0066cc">http://goparallel.sou=
rceforge.net/</font></a><br>
<br>
&gt; _______________________________________________<br>
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