From: Braydon Fuller <braydon@purse•io>
To: "David A. Harding" <dave@dtrt•org>,
Bitcoin Protocol Discussion
<bitcoin-dev@lists•linuxfoundation.org>
Subject: Re: [bitcoin-dev] Chain width expansion
Date: Fri, 4 Oct 2019 12:51:26 -0700 [thread overview]
Message-ID: <e9b9c972-7357-690c-2522-1928e6f84d48@purse.io> (raw)
In-Reply-To: <20191004082031.ns3pgzwh2zz2mxyc@ganymede>
On 10/4/19 1:20 AM, David A. Harding wrote:
> On Thu, Oct 03, 2019 at 05:38:36PM -0700, Braydon Fuller via bitcoin-dev wrote:
>> This paper describes a solution [to DoS attacks] that does not
>> require enabling or maintaining checkpoints and provides improved security.
>> [...]
>> The paper is available at:
>> https://bcoin.io/papers/bitcoin-chain-expansion.pdf
> [..] But I worry that the mechanisms could also be used to keep a node that
> synced to a long-but-lower-PoW chain on that false chain (or other false
> chain) indefinitely even if it had connections to honest peers that
> tried to tell it about the most-PoW chain.
Here is an example: An attacker eclipses a target node during the
initial block download; all of the target's outgoing peers are the
attacker. The attacker has a low work chain that is sent to the target.
The total chainwork for the low work chain is 0x09104210421039 at a
height of 593,975. The target is now in the state of a fully validated
low work dishonest chain. The target node then connects to an honest
peer and learns about the honest chain. The chainwork of the honest
chain is 0x085b67d9e07a751e53679d68 at a height of 593,975. The first
69,500 headers of the honest chain would have a delay, however the
remaining 52,4475 would not be delayed. Given a maximum of 5 seconds,
this would be a total delay of only 157 seconds.
next prev parent reply other threads:[~2019-10-04 19:51 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-04 0:38 Braydon Fuller
2019-10-04 8:20 ` David A. Harding
2019-10-04 19:51 ` Braydon Fuller [this message]
2019-10-11 21:24 ` Braydon Fuller
2019-10-04 23:31 ` Tier Nolan
2019-10-10 16:16 ` Braydon Fuller
2019-10-12 16:27 ` Tier Nolan
2019-10-12 17:56 ` Joachim Strömbergson
2019-10-12 20:46 ` Tier Nolan
2019-10-16 19:07 ` Braydon Fuller
2019-10-15 0:42 ` Braydon Fuller
2019-10-15 7:20 ` Joachim Strömbergson
2019-10-15 8:12 ` Braydon Fuller
2019-10-15 15:50 ` Joachim Strömbergson
2019-10-16 19:25 ` Braydon Fuller
2019-10-15 18:30 ` Tier Nolan
2019-10-15 0:38 ` Braydon Fuller
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