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From: Aaron Voisine <voisine@gmail.com>
To: Matt Whitlock <bip@mattwhitlock.name>
Cc: Bitcoin Development <bitcoin-development@lists.sourceforge.net>
Subject: Re: [Bitcoin-development] SPV clients and relaying double spends
Date: Thu, 25 Sep 2014 19:12:04 -0700	[thread overview]
Message-ID: <CACq0ZD55G7sAXuu-UxoVJuuk1rwxKKwAPg4qkRoTreD1X2fc9Q@mail.gmail.com> (raw)
In-Reply-To: <1447373.AzvO89eGJS@crushinator>

Something like that would be a great help for SPV clients that can't
detect double spends on their own. (still limited of course to sybil
attack concerns)

Aaron Voisine
breadwallet.com


On Thu, Sep 25, 2014 at 7:07 PM, Matt Whitlock <bip@mattwhitlock.name> wrote:
> What's to stop an attacker from broadcasting millions of spends of the same output(s) and overwhelming nodes with slower connections? Might it be a better strategy not to relay the actual transactions (after the first) but rather only propagate (once) some kind of double-spend alert?
>
>
> On Thursday, 25 September 2014, at 7:02 pm, Aaron Voisine wrote:
>> There was some discussion of having nodes relay double-spends in order
>> to alert the network about double spend attempts.
>>
>> A lot more users will be using SPV wallets in the future, and one of
>> the techniques SPV clients use to judge how likely a transaction is to
>> be confirmed is if it propagates across the network. I wonder if and
>> when double-spend relaying is introduced, if nodes should also send
>> BIP61 reject messages or something along those lines to indicate which
>> transactions those nodes believe to be invalid, but are relaying
>> anyway.
>>
>> This would be subject to sybil attacks, as is monitoring propagation,
>> however it does still increase the cost of performing a 0 confirmation
>> double spend attack on an SPV client above just relaying double-spends
>> without indicating if a node believes the transaction to be valid.
>>
>> Aaron Voisine
>> breadwallet.com
>



  reply	other threads:[~2014-09-26  2:12 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-09-26  2:02 [Bitcoin-development] SPV clients and relaying double spends Aaron Voisine
2014-09-26  2:07 ` Matt Whitlock
2014-09-26  2:12   ` Aaron Voisine [this message]
2014-09-26  2:16     ` Matt Whitlock
2014-09-26  2:37       ` Aaron Voisine
2014-09-26  3:34         ` Christophe Biocca
2014-09-28  2:55         ` Tom Harding
2014-09-28  5:15           ` [Bitcoin-development] replace-by-fee v0.9.3 release Peter Todd
2014-09-28 17:03             ` Luke Dashjr
2014-09-26 16:27       ` [Bitcoin-development] SPV clients and relaying double spends s7r

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