Defines the block number or timestamp until this transaction is locked, or 0 if the transaction is always locked.
Defines the block number or timestamp until this transaction is locked, or 0 if the transaction is always locked.
Questions tagged [locktime]
82 questions
12
votes
3 answers
Why is OP_CHECKLOCKTIMEVERIFY disabled by maximum sequence number?
In the code for OP_CHECKLOCKTIMEVERIFY i noticed that if the txin sequence number is maxxed out then the script will fail to validate. I'm wondering what the point of this is? Why would anybody ever submit a transaction that will fail to verify to…
mulllhausen
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12
votes
1 answer
Why are miners setting the locktime in coinbase transactions?
Some coinbase transactions have locktime values set. One such recent example is:
{
"txid": "5166cb509a5d786db33963a269ea08ff82a1c40d37d4fb828a394b0465cd5efd",
"hash": "075ffc5116296983aaa8286b4fdbaac101ba891a471cb835e9c532be926a7673",
…
TheCharlatan
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11
votes
3 answers
Can someone explain nLockTime?
I'm having a hard time understanding how nLockTime works. The Bitcoin wiki has an explanation that is confusing to me:
nLockTime is a parameter that can be attached to a transaction, that mandates a minimal time (specified in either unix time or…
gak
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10
votes
1 answer
How is locktime enforced in the standard client?
I am trying to study the locktime feature of transactions ( https://en.bitcoin.it/wiki/Protocol_specification#tx ). I have created some raw transactions in the testnet with different locktimes, but, when I send them, they are confirmed as usual. I…
halftimepad
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9
votes
1 answer
Why Bitcoin core creates time locked transactions by default?
I've noticed recently that Bitcoin Core is producing transactions with non-zero lock-time and sequence numbers of inputs being 0xFFFFFFFE, even though I didn't instruct it to do so. The lock-time appears to be current block number.
What is the…
Martin Habovštiak
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9
votes
2 answers
Why is the locktime set at transaction level while the sequence is set at input level?
Giacomo Zucco pointed out the oddity of there being one timelock field per transaction, but one sequence per input.
Even for the original use of determining the order of replacement, it would seem that only the maximum sequence is relevant in the…
Murch
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8
votes
3 answers
Can nLockTime TX be used to flood Mempools?
What would happen, if I would create a large number of large transactions with a very high nLockTime?
Would something stop me from filling not only the miners', but also regular nodes' mempools?
Would miners drop transactions with unreasonably high…
kermit
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8
votes
3 answers
What does "lock time" mean?
I got a transaction that is still not confirmed for about one week, and I can see a field called "Lock Time" that says:
Lock Time Block: 419382
https://blockchain.info/en/tx/ea445ae61c2906d43f8f8d73cfef2caefe3d63ae504da31a6a829cc35527faf6
What does…
Adrián
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7
votes
2 answers
nLockTime in Bitcoin Core
Currently, the Bitcoin Wiki states:
A part of the original Bitcoin implementation, nLockTime is a field that specifies the earliest time a transaction may be added to a valid block. A later Bitcoin soft fork allowed nLockTime to alternatively…
Martin Harrigan
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6
votes
1 answer
What does the 'n' in nLockTime and nSequence stand for?
I know what nLockTime and nSequence do, but I'm just curious about where the 'n' comes from. Thanks
Darius
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6
votes
1 answer
Sequence number semantics
Reading the following BIPs: 68, 112, 125, I got a few questions about the sematics of sequence numbers. As far as I understood, in version 1 transactions, sequence numbers have the following meaning:
If any input has a sequence less than…
Simone Bronzini
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5
votes
2 answers
Strange LockTime values in Electrum transactions?
Electrum includes a locktime in all transactions by default.
Usually the value is equal to the current block height, eg 592918, however it sometimes drops perhaps 20 or so blocks.
What is going on here?
Jonathan Cross
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5
votes
2 answers
What is transaction "finality"?
bitcoind IsFinalTx() as seen here checks the properties of a transaction in this order:
Is nLockTime exactly 0? That's final. return.
If it's not 0, is it below the current block height / time? If so, it's final. return.
Ensure that every tx input…
pinhead
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5
votes
1 answer
How can I make transaction output time locked?
Is it possible to submit some coins to some address and make them spendable after some period of time?
Like I want submit 1btc to address 1Kc24m... and make that output to be spendable after january 1st 2030.
Michal
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5
votes
1 answer
Is it possible to determine the total amount of timelocked Bitcoin?
Now that is possible to lock funds until a certain date (https://coinb.in/#newTimeLocked). How to calculate how many of all bitcoin in existence is locked until a certain date? Any service that does this?
Leonardo
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