19
votes
Accepted
Why is coinbase mentioned in a BIP?
The coinbase mentioned in BIP34 is not the company; it is referring to the first transaction in a Bitcoin block (which is special as it is allowed to bring new currency into circulation).
Coinbase-the-...
- 102k
14
votes
Accepted
Why do miners seem to be using consecutive letters for the Coinbase transaction text?
According to BIP 34 the coinbase transaction is required to start with the block height. The format is a single byte giving the count of bytes to follow (currently 3) and then the block height in ...
- 23k
12
votes
Accepted
Coinbase transaction's 100-block cooldown period
how is the output of a coinbase transaction (plus block's transaction fees) different than the outputs of any other transaction?
Because it's validity is tied to WHICH block it is included in. You ...
- 14k
11
votes
What is the coinbase?
David has already given a good explanation of the term coinbase, but I'd like to give further details on the coinbase transaction.
The coinbase transaction is a special type of transaction.
Every ...
- 72.6k
11
votes
Accepted
Why would a miner put an OP_RETURN in a coinbase transaction?
Every segwit block has one such OP_RETURN in the coinbase transaction: It's the Merkle root of the witness tree.
When the segwit softfork was activated, this included a fix to the third-party ...
- 72.6k
10
votes
Accepted
Why are there more than two transaction outputs in a coinbase transaction?
A coinbase transaction can have as many outputs as the miner who created it wants. You may see that there are not just one output for the reward, sometimes there are multiple outputs so that the ...
- 68.5k
9
votes
Why does this coinbase transaction have two op_return outputs?
Coinbase transactions have some special rules not shared by other transactions:
only one per block
must be the first transaction in the block
must have OP_RETURN output with witness commitment if ...
- 72.6k
8
votes
Accepted
Will a post-subsidy block with no transactions include a coinbase transaction?
Every Bitcoin block is required to have a coinbase transaction, regardless of fees or subsidy.
Additionally, every transaction (including the coinbase), must have at least one output (possibly 0-...
- 102k
8
votes
Accepted
Why does IsCoinBase() check if there is exactly one input?
A coinbase transaction is not allowed to have any other inputs, hence this check. Furthermore, because this check is part of consensus code, it is the definition for a coinbase transaction, so this ...
- 68.5k
8
votes
Accepted
Does the coinbase transaction have inputs?
Coinbase transactions must:
Have exactly 1 input.
That input must have prevout hash 0000...0000, and index 0xFFFFFFFF (an output which isn't actually spent).
The input's scriptSig must be between 2 ...
- 102k
7
votes
Limit order versus Market order
In a limit order, you specify how much of the asset (in this case BTC) you want to buy or sell, and the price you want. If there are matching orders on the book (e.g. someone who wants to sell at the ...
- 23k
7
votes
Accepted
Why does Bitcoin block 526,591 have a 6.25 (instead of 12.5) block reward?
There is a maximum limit on the block reward which is 12.5 BTC but nothing prevents a miner from claiming less than 12.5 BTC. In fact, there have been times when miners forgot to claim any bitcoin at ...
- 743
7
votes
Accepted
Was it always required for the Coinbase transaction to be the first transaction in a block?
This is not true. Code and code comments in v0.1.5 (the oldest tagged version in git) enforce that there always is a coinbase transaction and that it must always be the first. There cannot be a ...
- 68.5k
6
votes
Accepted
Why are coinbase transaction outputs greater than reward?
The extra 0.25058085 BTC is the sum of the transaction fees on the block (each transactions fee is the difference between the value of the transaction's inputs and the transaction's outputs).
As you ...
- 220
6
votes
Accepted
How is 10% transaction fee possible for a bitcoin transfer from coinbase to another exchange?
This is normal. You can see on https://bitcoinfees.earn.com/ that BTC 0.001 is a pretty average fee right now.
You should not think of it as a percentage, since the fee for a transaction is not ...
- 23k
6
votes
Accepted
Can a coinbase transaction have a segwit output?
Other than the total value needing to be correct (no more than the block reward plus fees), the outputs of a coinbase transaction are completely unrestricted and act the same as any other transaction.
- 15.4k
6
votes
Accepted
Why are miners setting the locktime in coinbase transactions?
Wang Chun of f2pool (@satofishi) said on Twitter: “We repurpose those 4 bytes to hold the stratum session data for faster reconnect.”
He went on to say: "The coinbase locktime is set to: ...
- 477
6
votes
Accepted
Where was the term "coinbase" first coined, who first used it?
The term "coinbase" was most likely coined by Satoshi through the IsCoinbase method of the CTransaction class. It was both part of the first publicly distributed version of the source code ...
- 7,027
5
votes
Accepted
Orphan block payment maturity
So is it that a miner who mined an orphan block receives the outputs of coinbase transaction but can never spend them?
Kind of.
In such a case the number of bitcoins in circulation would reduce ...
- 68.5k
5
votes
Accepted
What is the maximum number of bytes the coinbase scriptSig (coinbaseaux) can hold?
The maximum is 100 bytes and is checked and defined here: https://github.com/bitcoin/bitcoin/blob/master/src/consensus/tx_verify.cpp#L195
- 68.5k
5
votes
Accepted
Is there a maximum balance that a single address can hold?
Nope. Not 1 bit. A balance (in this context) is the sum of all UTXO's for a given address. There is no limit on the number of UTXO's or their total amount (from the perspective of how the blockchain ...
- 385
5
votes
Accepted
Some doubts regarding the structure of the Coinbase Transaction?
These are the requirements on the coinbase transaction that I am currently aware of.
The transaction is structured like every other transaction, though not all fields have the same meaning.
Version: ...
- 102k
5
votes
Accepted
What is OP_RETURN b9e11b6d?
The mentioned OP_RETURN output appears to be the footprint of merged-mining VCash, a Mimblewimble-based SHA-256d coin, with Bitcoin. I discovered this via the string 0xb9e11b6d appearing in these ...
- 72.6k
5
votes
Accepted
Can a coinbase transaction have more than one input?
No, coinbase transactions must have exactly one input, one with a coinbase field instead of referencing a UTXO to spend. Additional inputs are not allowed.
See also this related topic which describes ...
- 72.6k
5
votes
Accepted
Can a miner open a Lightning channel with a coinbase output?
After thinking some more about it: it would be impractical to open a channel with a coinbase output.
For one, there is the maturation period for coinbase outputs. Since coinbase outputs can only be ...
- 72.6k
5
votes
Different balances between fullnode and bitcoin explorer
You appear to have searched for a Pay to Public Key Hash (P2PKH) address, but the output on the coinbase transaction of block 200 is a Pay to Public Key (p2pk) output.
There is no address standard for ...
- 72.6k
4
votes
Accepted
Is the reward for successfully mining a block a transaction on the bitcoin network?
Yes, it is known as a coinbase transaction. It is the first transaction in every block and has some slightly different rules to all others. It has blank inputs, can not be spent for 100 confirmations, ...
- 15.4k
4
votes
Where is the source code that allows new coins to be generated?
You are looking for the method CAmount GetBlockSubsidy(int nHeight, const Consensus::Params& consensusParams) in validation.cpp.
CAmount GetBlockSubsidy(int nHeight, const Consensus::Params& ...
- 72.6k
4
votes
Where do the mined bitcoins go?
When miners are trying to find a block, they are doing so for a specific set of transactions. This set of transactions includes a special transaction, the coinbase transaction. It's the first ...
- 72.6k
4
votes
Accepted
Who issues the transaction of reward when a miner solves the block?
The miner itself includes a special transaction in the block called generation transaction. Every block only has a single generation transaction.
This generation transaction transfers the block ...
- 1,598
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