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From: Brian Erdelyi <brian.erdelyi@gmail.com>
In-Reply-To: <CAAt2M1-b7ByF0yVSmwD_nj3uUSo5GFOmH860n1k6oKX_sqvEkw@mail.gmail.com>
Date: Sun, 1 Feb 2015 08:49:05 -0400
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To: Natanael <natanael.l@gmail.com>
Cc: bitcoin-development@lists.sourceforge.net
Subject: Re: [Bitcoin-development] Proposal to address Bitcoin malware
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In online banking, the banks generate account numbers.  An attacker =
cannot generate their own account number and the likelihood of an =
attacker having the same account number that I am trying to transfer =
funds to is low and this is why OCRA is effective with online banking.

With Bitcoin, the Bitcoin address is comparable to the recipient=E2=80=99s=
 bank account number.   I now see how an an attacker can brute force the =
bitcoin address with vanitygen.  Is there any way to generate an 8 digit =
number from the bitcoin address that can be used to verify transactions =
in such a way (possibly with hashing?) that brute forcing a bitcoin =
address would take longer than a reasonable period of time (say 60 =
seconds) so a system could time out if a transaction was not completed =
in that time?

I=E2=80=99ve also looked into BIP70 (Payment Protocol) that claims =
protection against man-in-the-middle/man-in-the-browser (MitB) based =
attacks.  A common way to protect against this is with out-of-band =
transaction verification =
(http://en.wikipedia.org/wiki/Man-in-the-browser#Out-of-band_transaction_v=
erification =
<http://en.wikipedia.org/wiki/Man-in-the-browser#Out-of-band_transaction_v=
erification>).  I see how BIP 70 verifies the payment request, however, =
is there any way to verify that the transaction signed by the wallet =
matches the request before it is sent to the blockchain (and how can =
this support out of band verification)?  Perhaps this is something that =
can only be supported when sending money with web based wallets.

Brian Erdelyi=

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<html><head><meta http-equiv=3D"Content-Type" content=3D"text/html =
charset=3Dutf-8"></head><body style=3D"word-wrap: break-word; =
-webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" =
class=3D""><div class=3D""><br class=3D""></div><div class=3D"">In =
online banking, the banks generate account numbers. &nbsp;An attacker =
cannot generate their own account number and the likelihood of an =
attacker having the same account number that I am trying to transfer =
funds to is low and this is why OCRA is effective with online =
banking.</div><div class=3D""><br class=3D""></div><div class=3D"">With =
Bitcoin, the Bitcoin address is comparable to the recipient=E2=80=99s =
bank account number. &nbsp; I now see how an an attacker can brute force =
the bitcoin address with vanitygen. &nbsp;Is there any way to generate =
an 8 digit number from the bitcoin address that can be used to verify =
transactions in such a way (possibly with hashing?) that brute forcing a =
bitcoin address would take longer than a reasonable period of time (say =
60 seconds) so a system could time out if a transaction was not =
completed in that time?</div><div class=3D""><br class=3D""></div><div =
class=3D"">I=E2=80=99ve also looked into BIP70 (Payment Protocol) that =
claims protection against man-in-the-middle/man-in-the-browser (MitB) =
based attacks. &nbsp;A common way to protect against this is with =
out-of-band transaction verification (<a =
href=3D"http://en.wikipedia.org/wiki/Man-in-the-browser#Out-of-band_transa=
ction_verification" =
class=3D"">http://en.wikipedia.org/wiki/Man-in-the-browser#Out-of-band_tra=
nsaction_verification</a>). &nbsp;I see how BIP 70 verifies the payment =
request, however, is there any way to verify that the transaction signed =
by the wallet matches the request before it is sent to the blockchain =
(and how can this support out of band verification)? &nbsp;Perhaps this =
is something that can only be supported when sending money with web =
based wallets.</div><div class=3D""><br class=3D""></div><div =
class=3D"">Brian Erdelyi</div></body></html>=

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