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Date: Mon, 2 Feb 2015 22:57:04 +0200
Message-ID: <CAGKSKfW8seFosxzdSL-t8MJ4ewXPUpNh4BJQVVhMn4qPf_BtqQ@mail.gmail.com>
From: Joel Joonatan Kaartinen <joel.kaartinen@gmail.com>
To: Brian Erdelyi <brian.erdelyi@gmail.com>
Content-Type: multipart/alternative; boundary=047d7b33d9744d4f43050e213200
Cc: Bitcoin Dev <bitcoin-development@lists.sourceforge.net>
Subject: Re: [Bitcoin-development] Proposal to address Bitcoin malware
Precedence: list

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If the attacker has your desktop computer but not the mobile that's acting
as an independent second factor, how are you then supposed to be able to
tell you're not signing the correct transaction on the mobile? If the
address was replaced with the attacker's address, it'll look like
everything is ok.

- Joel

On Mon, Feb 2, 2015 at 9:58 PM, Brian Erdelyi <brian.erdelyi@gmail.com>
wrote:

>
> > Confusing or not, the reliance on multiple signatures as offering
> greater security than single relies on the independence of multiple
> secrets. If the secrets cannot be shown to retain independence in the
> envisioned threat scenario (e.g. a user's compromised operating system)
> then the benefit reduces to making the exploit more difficult to write,
> which, once written, reduces to no benefit. Yet the user still suffers th=
e
> reduced utility arising from greater complexity, while being led to belie=
ve
> in a false promise.
>
> Just trying to make sure I understand what you=E2=80=99re saying.  Are yo=
u eluding
> to that if two of the three private keys get compromised there is no gain
> in security?  Although the likelihood of this occurring is lower, it is
> possible.
>
> As more malware targets bitcoins I think the utility is evident.  Given
> how final Bitcoin transactions are, I think it=E2=80=99s worth trying to =
find
> methods to help verify those transactions (if a user deems it to be
> high-risk enough) before the transaction is completed.  The balance is
> trying to devise something that users do not find too burdensome.
>
> Brian Erdelyi
>
> -------------------------------------------------------------------------=
-----
> Dive into the World of Parallel Programming. The Go Parallel Website,
> sponsored by Intel and developed in partnership with Slashdot Media, is
> your
> hub for all things parallel software development, from weekly thought
> leadership blogs to news, videos, case studies, tutorials and more. Take =
a
> look and join the 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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<div dir=3D"ltr">If the attacker has your desktop computer but not the mobi=
le that&#39;s acting as an independent second factor, how are you then supp=
osed to be able to tell you&#39;re not signing the correct transaction on t=
he mobile? If the address was replaced with the attacker&#39;s address, it&=
#39;ll look like everything is ok.<div><br></div><div>- Joel<br><div class=
=3D"gmail_extra"><br><div class=3D"gmail_quote">On Mon, Feb 2, 2015 at 9:58=
 PM, Brian Erdelyi <span dir=3D"ltr">&lt;<a href=3D"mailto:brian.erdelyi@gm=
ail.com" target=3D"_blank">brian.erdelyi@gmail.com</a>&gt;</span> wrote:<br=
><blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1=
px #ccc solid;padding-left:1ex"><span class=3D""><br>
&gt; Confusing or not, the reliance on multiple signatures as offering grea=
ter security than single relies on the independence of multiple secrets. If=
 the secrets cannot be shown to retain independence in the envisioned threa=
t scenario (e.g. a user&#39;s compromised operating system) then the benefi=
t reduces to making the exploit more difficult to write, which, once writte=
n, reduces to no benefit. Yet the user still suffers the reduced utility ar=
ising from greater complexity, while being led to believe in a false promis=
e.<br>
<br>
</span>Just trying to make sure I understand what you=E2=80=99re saying.=C2=
=A0 Are you eluding to that if two of the three private keys get compromise=
d there is no gain in security?=C2=A0 Although the likelihood of this occur=
ring is lower, it is possible.<br>
<br>
As more malware targets bitcoins I think the utility is evident.=C2=A0 Give=
n how final Bitcoin transactions are, I think it=E2=80=99s worth trying to =
find methods to help verify those transactions (if a user deems it to be hi=
gh-risk enough) before the transaction is completed.=C2=A0 The balance is t=
rying to devise something that users do not find too burdensome.<br>
<div class=3D"HOEnZb"><div class=3D"h5"><br>
Brian Erdelyi<br>
---------------------------------------------------------------------------=
---<br>
Dive into the World of Parallel Programming. The Go Parallel Website,<br>
sponsored by Intel and developed in partnership with Slashdot Media, is you=
r<br>
hub for all things parallel software development, from weekly thought<br>
leadership blogs to news, videos, case studies, tutorials and more. Take a<=
br>
look and join the conversation now. <a href=3D"http://goparallel.sourceforg=
e.net/" target=3D"_blank">http://goparallel.sourceforge.net/</a><br>
_______________________________________________<br>
Bitcoin-development mailing list<br>
<a href=3D"mailto:Bitcoin-development@lists.sourceforge.net">Bitcoin-develo=
pment@lists.sourceforge.net</a><br>
<a href=3D"https://lists.sourceforge.net/lists/listinfo/bitcoin-development=
" target=3D"_blank">https://lists.sourceforge.net/lists/listinfo/bitcoin-de=
velopment</a><br>
</div></div></blockquote></div><br></div></div></div>

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