NLockTime - Revision history

NotATether: Add reference

2022-02-17T07:15:51Z

Add reference

← Older revision		Revision as of 07:15, 17 February 2022
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	For transaction relay, nLockTime must be <= the current block's height (block-based) or <= the current median time past (if time based). This ensures that the transaction can be included in the next block.		For transaction relay, nLockTime must be <= the current block's height (block-based) or <= the current median time past (if time based). This ensures that the transaction can be included in the next block.

	The behavior of a transaction's nLockTime can be modified by the sequence number of an input when using [[Script#Locktime\|OP_CHECKSEQUENCEVERIFY]]. That particular opcode is used inside input scripts to assert that the input's sequence number, which in normal transactions is set to UINT_MAX, is greater than or equal to the top item of the stack (usually the transaction's nLockTime). OP_CHECKSEQUENCEVERIFY is used in some proposed Layer 2 protocols, such as eltoo<ref>https://blockstream.com/eltoo.pdf</ref>.		The behavior of a transaction's nLockTime can be modified by the sequence number of an input when using [[Script#Locktime\|OP_CHECKSEQUENCEVERIFY]]. That particular opcode is used inside input scripts to assert that the input's sequence number, which in normal transactions is set to UINT_MAX, is greater than or equal to the top item of the stack (usually the transaction's nLockTime<ref>https://bitcoin.stackexchange.com/questions/38845/what-does-op-checksequenceverify-op-csv-do</ref>). OP_CHECKSEQUENCEVERIFY is used in some proposed Layer 2 protocols, such as eltoo<ref>https://blockstream.com/eltoo.pdf</ref>.

	==See Also==		==See Also==

NotATether: fix grammar

2022-02-17T07:12:33Z

fix grammar

← Older revision		Revision as of 07:12, 17 February 2022
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	For transaction relay, nLockTime must be <= the current block's height (block-based) or <= the current median time past (if time based). This ensures that the transaction can be included in the next block.		For transaction relay, nLockTime must be <= the current block's height (block-based) or <= the current median time past (if time based). This ensures that the transaction can be included in the next block.

	The behavior of a transaction's nLockTime can be modified by the sequence number of an input when using [[Script#Locktime\|OP_CHECKSEQUENCEVERIFY]]. That particular opcode is used inside input scripts to assert that the input's sequence number (which in normal transactions is set to UINT_MAX) is greater than or equal to the top item of the stack (usually the transaction's nLockTime). OP_CHECKSEQUENCEVERIFY is used in some proposed Layer 2 protocols, such as eltoo<ref>https://blockstream.com/eltoo.pdf</ref>.		The behavior of a transaction's nLockTime can be modified by the sequence number of an input when using [[Script#Locktime\|OP_CHECKSEQUENCEVERIFY]]. That particular opcode is used inside input scripts to assert that the input's sequence number, which in normal transactions is set to UINT_MAX, is greater than or equal to the top item of the stack (usually the transaction's nLockTime). OP_CHECKSEQUENCEVERIFY is used in some proposed Layer 2 protocols, such as eltoo<ref>https://blockstream.com/eltoo.pdf</ref>.

	==See Also==		==See Also==

NotATether: clarify definition of UINT_MAX

2022-02-17T07:11:51Z

clarify definition of UINT_MAX

← Older revision		Revision as of 07:11, 17 February 2022
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	{{stub}}		{{stub}}

	'''nLockTime''' is a parameter of a transaction, that, if any input indicates so (by having nSequence not equal to UINT_MAX), mandates a minimal time (specified in either unix time or block height), before which the transaction cannot be accepted into a block. If all inputs in a transaction have nSequence equal to UINT_MAX, then nLockTime is ignored.		'''nLockTime''' is a parameter of a transaction, that, if any input indicates so (by having nSequence not equal to UINT_MAX), mandates a minimal time (specified in either unix time or block height), before which the transaction cannot be accepted into a block. If all inputs in a transaction have nSequence equal to UINT_MAX (0xFFFFFFFF), then nLockTime is ignored.

	* If <code>nLockTime < 500000000</code>		* If <code>nLockTime < 500000000</code>
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	For transaction relay, nLockTime must be <= the current block's height (block-based) or <= the current median time past (if time based). This ensures that the transaction can be included in the next block.		For transaction relay, nLockTime must be <= the current block's height (block-based) or <= the current median time past (if time based). This ensures that the transaction can be included in the next block.

	The behavior of a transaction's nLockTime can be modified by the sequence number of an input when using [[Script#Locktime\|OP_CHECKSEQUENCEVERIFY]]. That particular opcode is used inside input scripts to assert that the input's sequence number (which in normal transactions is set to ~~0xFFFFFFFF to ignore it~~) is greater than or equal to the top item of the stack (usually the transaction's nLockTime). OP_CHECKSEQUENCEVERIFY is used in some proposed Layer 2 protocols, such as eltoo<ref>https://blockstream.com/eltoo.pdf</ref>.		The behavior of a transaction's nLockTime can be modified by the sequence number of an input when using [[Script#Locktime\|OP_CHECKSEQUENCEVERIFY]]. That particular opcode is used inside input scripts to assert that the input's sequence number (which in normal transactions is set to UINT_MAX) is greater than or equal to the top item of the stack (usually the transaction's nLockTime). OP_CHECKSEQUENCEVERIFY is used in some proposed Layer 2 protocols, such as eltoo<ref>https://blockstream.com/eltoo.pdf</ref>.

	==See Also==		==See Also==

NotATether: Document behavior when used with OP_CHECKSEQUENCEVERIFY

2022-02-17T07:10:31Z

Document behavior when used with OP_CHECKSEQUENCEVERIFY

← Older revision		Revision as of 07:10, 17 February 2022
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	For transaction relay, nLockTime must be <= the current block's height (block-based) or <= the current median time past (if time based). This ensures that the transaction can be included in the next block.		For transaction relay, nLockTime must be <= the current block's height (block-based) or <= the current median time past (if time based). This ensures that the transaction can be included in the next block.

			The behavior of a transaction's nLockTime can be modified by the sequence number of an input when using [[Script#Locktime\|OP_CHECKSEQUENCEVERIFY]]. That particular opcode is used inside input scripts to assert that the input's sequence number (which in normal transactions is set to 0xFFFFFFFF to ignore it) is greater than or equal to the top item of the stack (usually the transaction's nLockTime). OP_CHECKSEQUENCEVERIFY is used in some proposed Layer 2 protocols, such as eltoo<ref>https://blockstream.com/eltoo.pdf</ref>.

	==See Also==		==See Also==
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	* [https://github.com/bitcoin/bips/blob/master/bip-0113.mediawiki BIP113]		* [https://github.com/bitcoin/bips/blob/master/bip-0113.mediawiki BIP113]
	* The CHECKLOCKTIMEVERIFY opcode in [https://github.com/bitcoin/bips/blob/master/bip-0065.mediawiki BIP65]		* The CHECKLOCKTIMEVERIFY opcode in [https://github.com/bitcoin/bips/blob/master/bip-0065.mediawiki BIP65]

			==References==

	[[Category:Technical]]		[[Category:Technical]]
	{{lowercase}}		{{lowercase}}

Belcher: /* See Also */ Add link to transaction page

2021-06-10T12:25:32Z

MarkBLundeberg: Clarify that nLockTime cannot equal to the height of the block in which it is mined, and that the MTP is based on prior blocks only.

2019-11-06T16:15:49Z

Clarify that nLockTime cannot equal to the height of the block in which it is mined, and that the MTP is based on prior blocks only.

← Older revision		Revision as of 16:15, 6 November 2019
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	* If <code>nLockTime < 500000000</code>		* If <code>nLockTime < 500000000</code>
	** Specifies the block number ~~at (or~~ after) which this transaction can be ~~spent~~.		** Specifies the block number after which this transaction can be included in a block.
	* Otherwise		* Otherwise
	** Specifies the UNIX timestamp ~~at (or~~ after) which this transaction can be ~~spent~~.		** Specifies the UNIX timestamp after which this transaction can be included in a block.

	Note that since the adoption of BIP 113, the time-based nLockTime is compared to the 11-block [[median time past]], and not the block time itself. The median time past tends to lag the current unix time by about one hour (give or take), but unlike block time it increases monotonically.		Note that since the adoption of BIP 113, the time-based nLockTime is compared to the 11-block [[median time past]] (the median timestamp of the 11 blocks preceding the block in which the transaction is mined), and not the block time itself. The median time past tends to lag the current unix time by about one hour (give or take), but unlike block time it increases monotonically.

			For transaction relay, nLockTime must be <= the current block's height (block-based) or <= the current median time past (if time based). This ensures that the transaction can be included in the next block.

	==See Also==		==See Also==

MarkBLundeberg: emphasise it's at-or-after

2019-10-24T14:51:36Z

emphasise it's at-or-after

← Older revision		Revision as of 14:51, 24 October 2019
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	* If <code>nLockTime < 500000000</code>		* If <code>nLockTime < 500000000</code>
	** Specifies the block number at which this transaction can be spent.		** Specifies the block number at (or after) which this transaction can be spent.
	* Otherwise		* Otherwise
	** Specifies the UNIX timestamp at which this transaction can be spent.		** Specifies the UNIX timestamp at (or after) which this transaction can be spent.

	Note that since the adoption of BIP 113, the time-based nLockTime is compared to the 11-block [[median time past]], and not the block time itself. The median time past tends to lag the current unix time by about one hour (give or take), but unlike block time it increases monotonically.		Note that since the adoption of BIP 113, the time-based nLockTime is compared to the 11-block [[median time past]], and not the block time itself. The median time past tends to lag the current unix time by about one hour (give or take), but unlike block time it increases monotonically.

MarkBLundeberg: This page was erroneously attributing sequence lock time mechanics to the lock time. Fixed, and expanded regarding BIP 113.

2019-10-24T14:48:51Z

This page was erroneously attributing sequence lock time mechanics to the lock time. Fixed, and expanded regarding BIP 113.

← Older revision		Revision as of 14:48, 24 October 2019
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	'''nLockTime''' is a parameter of a transaction, that, if any input indicates so (by having nSequence not equal to UINT_MAX), mandates a minimal time (specified in either unix time or block height), before which the transaction cannot be accepted into a block. If all inputs in a transaction have nSequence equal to UINT_MAX, then nLockTime is ignored.		'''nLockTime''' is a parameter of a transaction, that, if any input indicates so (by having nSequence not equal to UINT_MAX), mandates a minimal time (specified in either unix time or block height), before which the transaction cannot be accepted into a block. If all inputs in a transaction have nSequence equal to UINT_MAX, then nLockTime is ignored.

	~~Since [https://github.com/bitcoin/bips/blob/master/bip-0068.mediawiki BIP68], the lock time can either be absolute or relative. Given a transaction,~~		* If <code>nLockTime < 500000000</code>
	* If the most significant bit (<code>1<<31</code>) of the '''nLockTime''' field is set (if the lock time is absolute)		** Specifies the block number at which this transaction can be spent.
	** If <code>nLockTime < 500000000</code>		* Otherwise
	*** Specifies the block number at which this transaction can be spent		** Specifies the UNIX timestamp at which this transaction can be spent.
	** Otherwise
	*** Specifies the UNIX timestamp at which this transaction can be spent		Note that since the adoption of BIP 113, the time-based nLockTime is compared to the 11-block [[median time past]], and not the block time itself. The median time past tends to lag the current unix time by about one hour (give or take), but unlike block time it increases monotonically.
	* Otherwise (if the ~~lock~~ time is ~~relative)~~
	** If the ~~23rd bit (<code>1<<22</code>) is~~ not ~~set~~
	*** The last 16 bits of the ~~'''nLockTime''' field specify a relative~~ time ~~in units of 512 seconds~~. The ~~transaction can only be included in a block if <code>spending_tx_block_time > spent_tx_block_time + nLockTime * 512</code>.~~
	** Otherwise
	*** The last 16 bits of the ~~'''nLockTime''' field specify a relative block height before which the transaction can not be included in a~~ block. ~~In other words it can be included if <code>spending_tx_block_height > spent_tx_block_height + nLockTime</code>~~

	==See Also==		==See Also==
	* lock_time in [[Protocol_specification#tx\|the protocol specification]]		* lock_time in [[Protocol_specification#tx\|the protocol specification]]
	* [[Timelock]]		* [[Timelock]]
	* [https://github.com/bitcoin/bips/blob/master/bip-~~0068~~.mediawiki ~~BIP68~~]		* [https://github.com/bitcoin/bips/blob/master/bip-0113.mediawiki BIP113]
	* The CHECKLOCKTIMEVERIFY opcode in [https://github.com/bitcoin/bips/blob/master/bip-0065.mediawiki BIP65]		* The CHECKLOCKTIMEVERIFY opcode in [https://github.com/bitcoin/bips/blob/master/bip-0065.mediawiki BIP65]
	* The CHECKSEQUENCEVERIFY opcode in [https://github.com/bitcoin/bips/blob/master/bip-00112.mediawiki BIP112]

	[[Category:Technical]]		[[Category:Technical]]
	{{lowercase}}		{{lowercase}}

Darosior: Add more details about the lock time interpretation.

2019-09-23T13:00:58Z

Add more details about the lock time interpretation.

← Older revision		Revision as of 13:00, 23 September 2019
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	'''nLockTime''' is a parameter of a transaction, that, if any input indicates so (by having nSequence not equal to UINT_MAX), mandates a minimal time (specified in either unix time or block height), before which the transaction cannot be accepted into a block. If all inputs in a transaction have nSequence equal to UINT_MAX, then nLockTime is ignored.		'''nLockTime''' is a parameter of a transaction, that, if any input indicates so (by having nSequence not equal to UINT_MAX), mandates a minimal time (specified in either unix time or block height), before which the transaction cannot be accepted into a block. If all inputs in a transaction have nSequence equal to UINT_MAX, then nLockTime is ignored.

			Since [https://github.com/bitcoin/bips/blob/master/bip-0068.mediawiki BIP68], the lock time can either be absolute or relative. Given a transaction,
	Since [https://github.com/bitcoin/bips/blob/master/bip-0068.mediawiki BIP68], the ~~'''nLockTime'''~~ can ~~specify a~~ relative ~~lock time~~. Given a transaction,		* If the most significant bit (<code>1<<31</code>) of the '''nLockTime''' field is set (if the lock time is absolute)
	* If the most significant bit (1<<31) is ~~not~~ set		** If <code>nLockTime < 500000000</code>
	** If the 23rd bit (1<<22) is set		*** Specifies the block number at which this transaction can be spent
			** Otherwise
			*** Specifies the UNIX timestamp at which this transaction can be spent
			* Otherwise (if the lock time is relative)
			** If the 23rd bit (<code>1<<22</code>) is not set
	*** The last 16 bits of the '''nLockTime''' field specify a relative time in units of 512 seconds. The transaction can only be included in a block if <code>spending_tx_block_time > spent_tx_block_time + nLockTime * 512</code>.		*** The last 16 bits of the '''nLockTime''' field specify a relative time in units of 512 seconds. The transaction can only be included in a block if <code>spending_tx_block_time > spent_tx_block_time + nLockTime * 512</code>.
	** Otherwise		** Otherwise
	*** The last 16 bits of the '''nLockTime''' field specify a relative block height before which the transaction can not be included in a block. In other words it can be included if <code>spending_tx_block_height > spent_tx_block_height + nLockTime</code>		*** The last 16 bits of the '''nLockTime''' field specify a relative block height before which the transaction can not be included in a block. In other words it can be included if <code>spending_tx_block_height > spent_tx_block_height + nLockTime</code>
	* Otherwise
	** the transaction can be included in any block

	==See Also==		==See Also==

Darosior: Correct the BIP68 additions

2019-09-23T12:49:59Z

Correct the BIP68 additions

← Older revision		Revision as of 12:49, 23 September 2019
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	Since [https://github.com/bitcoin/bips/blob/master/bip-0068.mediawiki BIP68], ~~a new meaning has been given to~~ the '''nLockTime''' ~~and '''nSequence''' fields~~. Given a transaction,		Since [https://github.com/bitcoin/bips/blob/master/bip-0068.mediawiki BIP68], the '''nLockTime''' can specify a relative lock time. Given a transaction,
	* If the most significant bit (1<<31) is set		* If the most significant bit (1<<31) is not set
	** If the 23rd bit (1<<22) is set		** If the 23rd bit (1<<22) is set
	*** ~~Specifies~~ a time in units of 512 seconds. The transaction can only be included in a block if <code>~~block_time~~ > nLockTime * 512</code>.		*** The last 16 bits of the '''nLockTime''' field specify a relative time in units of 512 seconds. The transaction can only be included in a block if <code>spending_tx_block_time > spent_tx_block_time + nLockTime * 512</code>.
	** Otherwise		** Otherwise
	*** ~~Specifies~~ a block height before which the transaction can not be included in a block.		*** The last 16 bits of the '''nLockTime''' field specify a relative block height before which the transaction can not be included in a block. In other words it can be included if <code>spending_tx_block_height > spent_tx_block_height + nLockTime</code>
	* Otherwise		* Otherwise
	** the transaction can be included in any block		** the transaction can be included in any block

← Older revision		Revision as of 12:25, 10 June 2021
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	==See Also==		==See Also==
	* lock_time in [[Protocol_specification#tx\|the protocol specification]]		* lock_time in [[Protocol_specification#tx\|the protocol specification]]
			* [[Transaction]]
	* [[Timelock]]		* [[Timelock]]
	* [https://github.com/bitcoin/bips/blob/master/bip-0113.mediawiki BIP113]		* [https://github.com/bitcoin/bips/blob/master/bip-0113.mediawiki BIP113]