Subject: [bitcoin-dev] BIP - Block size doubles at each reward halving with max block size of 32M

From: John Sacco <[email-masked]>
Date: Thu, 12 Nov 2015 18:47:31 -0500

Hi Devs,

Please consider the draft proposal below for peer review.

Thanks,

John

BIP

  BIP: ?

  Title: Block size doubles at each reward halving with max block size of
32M

  Author: John Sacco <[email-masked]>

  Status: Draft

  Type: Standards Track

  Created: 2015-11-11

Abstract

Change max block size to 2MB at next block subsidy halving, and double the
block size at each subsidy halving until reaching 32MB.

Copyright

This proposal belongs in the public domain. Anyone can use this text for
any purpose with proper attribution to the author.

Motivation

1.    Gradually restores block size to the default 32 MB setting originally
implemented by Satoshi.

2.    Initial increase to 2MB at block halving in July 2016 would have
minimal impact to existing nodes running on most hardware and networks.

3.    Long term solution that does not make enthusiastic assumptions
regarding future bandwidth and storage availability estimates.

4.    Maximum block size of 32MB allows peak usage of ~100 tx/sec by year
2031.

5.    Exercise network upgrade procedure during subsidy reward halving, a
milestone event with the goal of increasing awareness among miners and node
operators.

Specification

1.    Increase the maximum block size to 2MB when block 630,000 is reached
and 75% of the last 1,000 blocks have signaled support.

2.    Increase maximum block size to 4MB at block 840,000.

3.    Increase maximum block size to 8MB at block 1,050,000.

4.    Increase maximum block size to 16MB at block 1,260,000.

5.    Increase maximum block size to 32MB at block 1,470,000.

Backward compatibility

All older clients are not compatible with this change. The first block
larger than 1M will create a network partition excluding not-upgraded
network nodes and miners.

Rationale

While more comprehensive solutions are developed, an increase to the block
size is needed to continue network growth. A longer term solution is needed
to prevent complications associated with additional hard forks. It should
also increase at a gradual rate that retains and allows a large
distribution of full nodes.  Scheduling this hard fork to occur no earlier
than the subsidy halving in 2016 has the goal of simplifying the
communication outreach needed to achieve consensus, while also providing a
buffer of time to make necessary preparations.