BIP 0111: Difference between revisions

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Update BIP text with latest version from https://github.com/bitcoin/bips/blob/b5723035e23896d0/bip-0111.mediawiki
 
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<pre>
<pre>
   BIP: 111
   BIP: 111
  Layer: Peer Services
   Title: NODE_BLOOM service bit
   Title: NODE_BLOOM service bit
   Author: Matt Corallo <bip@bluematt.me>, Peter Todd <pete@petertodd.org>
   Author: Matt Corallo <bip111@bluematt.me>
   Status: Draft
          Peter Todd <pete@petertodd.org>
  Comments-Summary: No comments yet.
  Comments-URI: https://github.com/bitcoin/bips/wiki/Comments:BIP-0111
   Status: Proposed
   Type: Standards Track
   Type: Standards Track
   Created: 2015-08-20
   Created: 2015-08-20
  License: PD
</pre>
</pre>


{{BipMoved|bip-0111.mediawiki|BIP 0111}}
== Abstract ==
 
This BIP extends BIP 37, Connection Bloom filtering, by defining a
service bit to allow peers to advertise that they support bloom filters
explicitly. It also bumps the protocol version to allow peers to
identify old nodes which allow bloom filtering of the connection despite
lacking the new service bit.
 
 
== Motivation ==
 
BIP 37 did not specify a service bit for the bloom filter service, thus
implicitly assuming that all nodes that serve peers data support it.
However, the connection filtering algorithm proposed in BIP 37, and
implemented in several clients today, has been shown to provide little
to no privacy<ref>http://eprint.iacr.org/2014/763</ref>, as well as being a large DoS risk on some nodes<ref>[http://lists.linuxfoundation.org/pipermail/bitcoin-dev/2013-July/003044.html] is one example where the issues were found, though others independently discovered issues as well. Sample DoS exploit code available at https://github.com/petertodd/bloom-io-attack.</ref>.
Thus, allowing node operators to disable connection bloom filtering is a
much-needed feature.
 
 
== Specification ==
 
The following protocol bit is added:
 
<pre>
    NODE_BLOOM = (1 << 2)
</pre>
 
Nodes which support bloom filters should set that protocol bit.
Otherwise it should remain unset. In addition the protocol version is
increased from 70002 to 70011 in the reference implementation. It is
often the case that nodes which have a protocol version smaller than
70011, but larger than 70000 support bloom filtered connections without
the NODE_BLOOM bit set, however clients which require bloom filtered
connections should avoid making this assumption.
 
NODE_BLOOM is distinct from NODE_NETWORK, and it is legal to advertise
NODE_BLOOM but not NODE_NETWORK (though there is little reason to do
so now, some proposals may make this more useful in the future)
 
If a node does not support bloom filters but receives a "filterload",
"filteradd", or "filterclear" message from a peer the node should
disconnect that peer immediately. For backwards compatibility, in
initial implementations, nodes may choose to only disconnect nodes which
have the new protocol version set and attempt to send a filter command.
 
While outside the scope of this BIP it is suggested that DNS seeds and
other peer discovery mechanisms support the ability to specify the
services required; current implementations simply check only that
NODE_NETWORK is set.
 
 
== Design rational ==
 
A service bit was chosen as applying a bloom filter is a service.
 
The increase in protocol version is for backwards compatibility. In
initial implementations, old nodes which are not yet aware of NODE_BLOOM
and use a protocol version < 70011 may still send filter messages to a
node without NODE_BLOOM. This feature may be removed after there are
sufficient NODE_BLOOM nodes available and SPV clients have upgraded,
allowing node operators to fully close the bloom-related DoS vectors.
 
 
== Reference Implementation ==
 
https://github.com/bitcoin/bitcoin/pull/6579
 
 
== Copyright ==
 
This document is placed in the public domain.
 
 
== References ==
<references>

Latest revision as of 18:00, 24 September 2019

This page describes a BIP (Bitcoin Improvement Proposal).
Please see BIP 2 for more information about BIPs and creating them. Please do not just create a wiki page.

Please do not modify this page. This is a mirror of the BIP from the source Git repository here.

 
  BIP: 111
  Layer: Peer Services
  Title: NODE_BLOOM service bit
  Author: Matt Corallo <bip111@bluematt.me>
          Peter Todd <pete@petertodd.org>
  Comments-Summary: No comments yet.
  Comments-URI: https://github.com/bitcoin/bips/wiki/Comments:BIP-0111
  Status: Proposed
  Type: Standards Track
  Created: 2015-08-20
  License: PD

Abstract

This BIP extends BIP 37, Connection Bloom filtering, by defining a service bit to allow peers to advertise that they support bloom filters explicitly. It also bumps the protocol version to allow peers to identify old nodes which allow bloom filtering of the connection despite lacking the new service bit.


Motivation

BIP 37 did not specify a service bit for the bloom filter service, thus implicitly assuming that all nodes that serve peers data support it. However, the connection filtering algorithm proposed in BIP 37, and implemented in several clients today, has been shown to provide little to no privacy[1], as well as being a large DoS risk on some nodes[2]. Thus, allowing node operators to disable connection bloom filtering is a much-needed feature.


Specification

The following protocol bit is added: 

    NODE_BLOOM = (1 << 2)

Nodes which support bloom filters should set that protocol bit. Otherwise it should remain unset. In addition the protocol version is increased from 70002 to 70011 in the reference implementation. It is often the case that nodes which have a protocol version smaller than 70011, but larger than 70000 support bloom filtered connections without the NODE_BLOOM bit set, however clients which require bloom filtered connections should avoid making this assumption.

NODE_BLOOM is distinct from NODE_NETWORK, and it is legal to advertise NODE_BLOOM but not NODE_NETWORK (though there is little reason to do so now, some proposals may make this more useful in the future)

If a node does not support bloom filters but receives a "filterload", "filteradd", or "filterclear" message from a peer the node should disconnect that peer immediately. For backwards compatibility, in initial implementations, nodes may choose to only disconnect nodes which have the new protocol version set and attempt to send a filter command.

While outside the scope of this BIP it is suggested that DNS seeds and other peer discovery mechanisms support the ability to specify the services required; current implementations simply check only that NODE_NETWORK is set.


Design rational

A service bit was chosen as applying a bloom filter is a service.

The increase in protocol version is for backwards compatibility. In initial implementations, old nodes which are not yet aware of NODE_BLOOM and use a protocol version < 70011 may still send filter messages to a node without NODE_BLOOM. This feature may be removed after there are sufficient NODE_BLOOM nodes available and SPV clients have upgraded, allowing node operators to fully close the bloom-related DoS vectors.


Reference Implementation

https://github.com/bitcoin/bitcoin/pull/6579


Copyright

This document is placed in the public domain.


References

<references>

  1. ↑ http://eprint.iacr.org/2014/763
  2. ↑ [1] is one example where the issues were found, though others independently discovered issues as well. Sample DoS exploit code available at https://github.com/petertodd/bloom-io-attack.
Retrieved from "https://en.bitcoin.it/w/index.php?title=BIP_0111&oldid=66869"