This is a draft BIP proposal to redeploy segwit using BIP-8, from the day after the current BIP9 segwit times out.

This BIP could be deployed long before Nov 15th 2016, for example in July allowing wide deployment to begin soon. The timeout (and this useractivation) could be set to roughly a year from then. However, considering around 70% of nodes upgraded to witness capability within 5-6 months, I personally think we could reduce the time, especially considering how much people want segwit - but I understand the need for more caution in Bitcoin.

Preliminary dates are deploy within a couple months, startdate Nov 16th 2017, BIP8 timeout July 4th 2018.


<pre>
  BIP: ?
  Layer: Consensus (soft fork)
  Title: Segwit deployment with versionbits and guaranteed lock-in
  Author: Shaolin Fry <shaolinfry@protonmail.ch>
  Comments-Summary: No comments yet.
  Comments-URI: https://github.com/bitcoin/bips/wiki/Comments:BIP-????
  Status: Draft
  Type: Standards Track
  Created: 2017-04-14
  License: BSD-3-Clause
           CC0-1.0
</pre>

==Abstract==

This document specifies a user activated soft fork for BIP141, BIP143 and BIP147 using versionbits with guaranteed lock-in.

==Motivation==

Miners have been reluctant to signal the BIP9 segwit deployment despite a large portion of the Bitcoin ecosystem who want the soft fork activated. This BIP specifies a user activated soft fork (UASF) that deploys segwit again using versionbits with guaranteed lock-in on timeout if the BIP is not already locked-in or activated by the timeout. This ensures users have sufficient time to prepare and no longer require a miner supermajority, while still allowing for an earlier miner activated soft fork (MASF).

==Reference implementation==

https://github.com/bitcoin/bitcoin/compare/master...shaolinfry:uasegwit-flagday

==Specification==

This deployment will set service bit (1<<5) as NODE_UAWITNESS.

==Deployment==

This BIP will be deployed by BIP8 with the name "uasegwit" and using bit 2.

For Bitcoin mainnet, the BIP8 starttime will be midnight 16 November 2017 UTC (Epoch timestamp 1510790400) and BIP8 timeout will be 4 July 2018 UTC (Epoch timestamp 1530662400).

For Bitcoin testnet, segwit is already activated so no deployment is specified.

==Rationale==

This BIP can be deployed well in advance of the BIP8 '''starttime''' so that the '''timeout''' will be sufficiently far in the future to allow Bitcoin users to uprgade in preparation.

The '''starttime''' of this BIP is after the BIP9 "segwit" timeout to remove compatibility issues with old nodes.

==References==

https://github.com/bitcoin/bips/blob/master/bip-0008.mediawiki

https://github.com/bitcoin/bips/blob/master/bip-0009.mediawiki

https://github.com/bitcoin/bips/blob/master/bip-0141.mediawiki

https://github.com/bitcoin/bips/blob/master/bip-0143.mediawiki

https://github.com/bitcoin/bips/blob/master/bip-0147.mediawiki

==Copyright==

This document is dual licensed as BSD 3-clause, and Creative Commons CC0 1.0 Universal.