From: Gregory Maxwell <gmaxwell@gmail•com>
To: Gavin Andresen <gavinandresen@gmail•com>
Cc: bitcoin-dev@lists•linuxfoundation.org
Subject: Re: [bitcoin-dev] For discussion: limit transaction size to mitigate CVE-2013-2292
Date: Mon, 20 Jul 2015 20:55:57 +0000 [thread overview]
Message-ID: <CAAS2fgRBa47ye-ouV2jDe16MJFCKxYh0zF0Jw4BTwzpXVKgwOg@mail.gmail.com> (raw)
In-Reply-To: <CABsx9T30aUx+Leb2HXx2QrMT8R_eTXV9hiC99av957645iQm1Q@mail.gmail.com>
On Mon, Jul 20, 2015 at 7:10 PM, Gavin Andresen via bitcoin-dev
<bitcoin-dev@lists•linuxfoundation.org> wrote:
> Mitigate a potential CPU exhaustion denial-of-service attack by limiting
> the maximum size of a transaction included in a block.
This seems like a fairly indirect approach. The resource being watched
for is not the size (otherwise two transactions for 200k would be
strictly worse than one 200k transactions) but the potential of N^2
costs related to repeated hashing in checksig; which this ignores.
The cost of the indirection is forclosing future applications which
involve larger signatures but have no quadratic component and are thus
fast to verify-- or requring yet another hard fork to remove the
limit, or a kludgy soft fork that splits the same data across two
"transactions" which get processed as a unit... all would be
unfortunate.
Alternative 1 sounds more attractive to be for this reason as it's more direct.
next prev parent reply other threads:[~2015-07-20 20:55 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-20 19:10 Gavin Andresen
2015-07-20 19:43 ` Tier Nolan
2015-07-20 20:30 ` Gavin Andresen
2015-07-20 19:58 ` Ross Nicoll
2015-07-20 20:55 ` Gregory Maxwell [this message]
2015-07-21 18:09 ` Gavin Andresen
2015-07-21 18:18 ` Jeremy Rubin
2015-07-23 15:41 ` Gavin Andresen
2015-07-24 20:59 ` Gavin Andresen
2015-07-25 0:47 ` odinn
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