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Diffstat (limited to 'bip-0113.mediawiki')
| -rw-r--r-- | bip-0113.mediawiki | 47 |
1 files changed, 15 insertions, 32 deletions
diff --git a/bip-0113.mediawiki b/bip-0113.mediawiki index 190fb4c..7497f50 100644 --- a/bip-0113.mediawiki +++ b/bip-0113.mediawiki @@ -2,7 +2,7 @@ BIP: 113 Title: Median time-past as endpoint for lock-time calculations Author: Thomas Kerin <me@thomaskerin.io> - Mark Friedenbach <mark@friedenbach.org> + Mark Friedenbach <mark@friedenbach.org> Status: Draft Type: Standards Track Created: 2015-08-10 @@ -34,8 +34,9 @@ value to monotonically advance, thereby removing the capability for miners to claim more transaction fees by lying about the timestamps of their block. -This proposal seeks to ensure reliable behaviour in locktime calculations as -required by BIP65 (CHECKLOCKTIMEVERIFY), BIP68 (sequence numbers), and BIP112 (CHECKSEQUENCEVERIFY). +This proposal seeks to ensure reliable behaviour in locktime calculations +as required by BIP65 (CHECKLOCKTIMEVERIFY) and matching the behavior of +BIP68 (sequence numbers) and BIP112 (CHECKSEQUENCEVERIFY). ==Specification== @@ -58,11 +59,10 @@ block time for the purpose of checking lock-time constraints: return pbegin[(pend - pbegin)/2]; } -Lock-time constraints are checked by the consensus method IsFinalTx(), -or LockTime() under BIP68. These methods take the block time as one -parameter. This BIP proposes that after activation calls to -IsFinalTx() or LockTime() within consensus code use the return value -of `GetMedianTimePast(pindexPrev)` instead. +Lock-time constraints are checked by the consensus method IsFinalTx(). +This method takes the block time as one parameter. This BIP proposes +that after activation calls to IsFinalTx() within consensus code use +the return value of `GetMedianTimePast(pindexPrev)` instead. A reference implementation of this proposal is provided by the following pull request: @@ -72,33 +72,13 @@ https://github.com/bitcoin/bitcoin/pull/6566 ==Deployment== -We reuse the double-threshold switchover mechanism from BIPs 34 and -66, with the same thresholds, but for nVersion = 8. The new rules are -in effect for every block (at height H) with nVersion = 8 and at least -750 out of 1000 blocks preceding it (with heights H-1000..H-1) also -have nVersion = 8. Furthermore, when 950 out of the 1000 blocks -preceding a block do have nVersion = 8, nVersion = 3 blocks become -invalid, and all further blocks enforce the new rules. +This BIP is to be deployed by "versionbits" BIP9 using bit 0. -When assessing the block version as mask of ~0x20000007 must be applied -to work around the complications caused by -[http://lists.linuxfoundation.org/pipermail/bitcoin-dev/2015-August/010396.html BIP101's premature use] -of the [https://gist.github.com/sipa/bf69659f43e763540550 undecided version bits proposal]. +For Bitcoin '''mainnet''', the BIP9 '''starttime''' will be midnight 1st May 2016 UTC (Epoch timestamp 1462060800) and BIP9 '''timeout''' will be midnight 1st May 2017 UTC (Epoch timestamp 1493596800). -By applying ~0x20000007 with nVersion = 8, the thresholds should be tested -comparing block nVersion >= 4 as this will save a bit for future use. +For Bitcoin '''testnet''', the BIP9 '''starttime''' will be midnight 1st March 2016 UTC (Epoch timestamp 1456790400) and BIP9 '''timeout''' will be midnight 1st May 2017 UTC (Epoch timestamp 1493596800). -It is recommended that this soft-fork deployment trigger include other related -proposals for improving Bitcoin's lock-time capabilities, including: - -[https://github.com/bitcoin/bips/blob/master/bip-0065.mediawiki BIP 65]: -CHECKLOCKTIMEVERIFY, - -[https://github.com/bitcoin/bips/blob/master/bip-0068.mediawiki BIP 68]: -Consensus-enforced transaction replacement signalled via sequence numbers, - -and [https://github.com/bitcoin/bips/blob/master/bip-0112.mediawiki BIP 112]: -CHECKSEQUENCEVERIFY. +This BIP must be deployed simultaneously with BIP68 and BIP112 using the same deployment mechanism. ==Acknowledgements== @@ -121,6 +101,9 @@ concerns with existing protocols. ==References== + +[https://github.com/bitcoin/bips/blob/master/bip-0009.mediawiki BIP9: Versionbits] + [https://github.com/bitcoin/bips/blob/master/bip-0065.mediawiki BIP65: OP_CHECKLOCKTIMEVERIFY] [https://github.com/bitcoin/bips/blob/master/bip-0068.mediawiki BIP68: Consensus-enforced transaction replacement signaled via sequence numbers] |