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In-Reply-To: <96328209-9249-44BC-957A-4EF8DE014E2D@jonasschnelli.ch>
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	<96328209-9249-44BC-957A-4EF8DE014E2D@jonasschnelli.ch>
From: Adam Ritter <aritter@gmail.com>
Date: Sat, 30 Sep 2017 11:35:05 +0200
Message-ID: <CAKuKjyWN-K9xSuwebtTxEG7Em6jSLsKdE8VY2n72FBdpeycZxA@mail.gmail.com>
To: Dan Libby <dan@osc.co.cr>, Jonas Schnelli <dev@jonasschnelli.ch>, 
	Bitcoin Protocol Discussion <bitcoin-dev@lists.linuxfoundation.org>
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Subject: Re: [bitcoin-dev] Paper Wallet support in bitcoin-core
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I'm happy to help with secure paper wallet support. Bitcoin core is already
used offline by the Glacier Protocol, though there's no official offline
support.

I extended the Glacier Protocol with an extra password derivation function.
I used Scrypt with 2GB RAM requirement, though maybe using Argon2id V1.3
would be better.

Also I'd prefer using BIP45 Multisig HD Wallets over a multisig address, as
in the current Glacier Protocol implementation the redeem key is public
because of the test withdrawal transaction.

On Sat, Sep 30, 2017 at 6:49 AM, Jonas Schnelli via bitcoin-dev <
bitcoin-dev@lists.linuxfoundation.org> wrote:

>
> > Hi,
> >
> > I'm writing to suggest and discuss the addition of paper wallet
> > functionality in bitcoin-core software, starting with a single new RPC
> > call: genExternalAddress [type].
> >
>
> AFAIK, client implementations such as your proposal are off-topic for this
> ML.
> Better use bitcoin-core-dev (ML or IRC) or Github (bitcoin/bitcoin) for
> such proposals.
>
>
> > On 09/29/2017 02:03 PM, Luke Dashjr wrote:
> > Paper wallets are a safety hazard, insecure, and generally not advisable.
> >
>
> I have to agree with Luke.
> And I would also extend those concerns to BIP39 plaintext paper backups.
>
> IMO, private keys should be generated and used (signing) on a trusted,
> minimal and offline hardware/os. They should never leave the device over
> the channel used for the signing I/O. Users should have no way to view or
> export the private keys (expect for the seed backup). Backups should be
> encrypted (whoever finds the paper backup should need a second factor to
> decrypt) and the restore process should be footgun-safe (especially the
> lost-passphrase deadlock).
>
>
> /jonas
>
> _______________________________________________
> bitcoin-dev mailing list
> bitcoin-dev@lists.linuxfoundation.org
> https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev
>
>

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<div dir=3D"ltr">I&#39;m happy to help with secure paper wallet support. Bi=
tcoin core is already used offline by the Glacier Protocol, though there=
9;s no official offline support.<div><br><div>I extended the Glacier Protoc=
ol with an extra password derivation function. I used Scrypt with 2GB RAM r=
equirement, though maybe using Argon2id V1.3 would be better.</div></div><d=
iv><br></div><div>Also I&#39;d prefer using BIP45 Multisig HD Wallets over =
a multisig address, as in the current Glacier Protocol implementation the r=
edeem key is public because of the test withdrawal transaction.</div><div c=
lass=3D"gmail_extra"><br><div class=3D"gmail_quote">On Sat, Sep 30, 2017 at=
 6:49 AM, Jonas Schnelli via bitcoin-dev <span dir=3D"ltr">&lt;<a href=3D"m=
ailto:bitcoin-dev@lists.linuxfoundation.org" target=3D"_blank">bitcoin-dev@=
lists.<wbr>linuxfoundation.org</a>&gt;</span> wrote:<br><blockquote class=
=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1px #ccc solid;padd=
ing-left:1ex"><span><br>
&gt; Hi,<br>
&gt;<br>
&gt; I&#39;m writing to suggest and discuss the addition of paper wallet<br=
>
&gt; functionality in bitcoin-core software, starting with a single new RPC=
<br>
&gt; call: genExternalAddress [type].<br>
&gt;<br>
<br>
</span>AFAIK, client implementations such as your proposal are off-topic fo=
r this ML.<br>
Better use bitcoin-core-dev (ML or IRC) or Github (bitcoin/bitcoin) for suc=
h proposals.<br>
<span><br>
<br>
&gt; On 09/29/2017 02:03 PM, Luke Dashjr wrote:<br>
&gt; Paper wallets are a safety hazard, insecure, and generally not advisab=
le.<br>
&gt;<br>
<br>
</span>I have to agree with Luke.<br>
And I would also extend those concerns to BIP39 plaintext paper backups.<br=
>
<br>
IMO, private keys should be generated and used (signing) on a trusted, mini=
mal and offline hardware/os. They should never leave the device over the ch=
annel used for the signing I/O. Users should have no way to view or export =
the private keys (expect for the seed backup). Backups should be encrypted =
(whoever finds the paper backup should need a second factor to decrypt) and=
 the restore process should be footgun-safe (especially the lost-passphrase=
 deadlock).<br>
<br>
<br>
/jonas<br>
<br>______________________________<wbr>_________________<br>
bitcoin-dev mailing list<br>
<a href=3D"mailto:bitcoin-dev@lists.linuxfoundation.org" target=3D"_blank">=
bitcoin-dev@lists.linuxfoundat<wbr>ion.org</a><br>
<a href=3D"https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev" =
rel=3D"noreferrer" target=3D"_blank">https://lists.linuxfoundation.<wbr>org=
/mailman/listinfo/bitcoin-d<wbr>ev</a><br>
<br></blockquote></div><br></div></div>

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