Questions tagged [coinbase-transaction]

The "coinbase transaction" is the transaction inside a block that pays the miner his block reward.

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31
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2answers
11k views

What is the coinbase?

I searched the bitcoin wiki and found references to coinbase, but no clear cut explanation of what exactly it is. I know that miners can tag their coinbases (that is how some sites tell who mined a ...
24
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2answers
6k views

What is the block maturation time?

I was reading the wiki article about the blockchain and I didn't understand the part in bold: When a block becomes an orphan block, all of its valid transactions are re-added to the pool of ...
18
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4answers
7k views

How can one embed custom data in block headers?

Some mining pool admins put custom data in block headers, like prayers. How do they do that? Where can I see that data for myself?
15
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2answers
7k views

What is the format of the coinbase transaction?

I'm trying to understand the format of the coinbase transaction. I've read that it is arbitrary and not specified. I'm wondering because I need to generate mining work and create an internal pool. As ...
15
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1answer
1k views

What happens when a miner does not claim all fees/generated coins?

Suppose that a miner for some reason has the generation transaction of their blocks not take all the possible coins. This can happen for a variety of reasons, almost all of which are bugs: An off-by-...
11
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1answer
753 views

Is there a limit to how much extra data can be put into blocks via scripts?

According to this answer, miners can include extra data in blocks. Is there an upper bound to how much a miner can add? How much?
9
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1answer
3k views

Why does the default miner implementation use pay-to-pubkey?

Looking at the v0.9.3 source in miner.cpp: CBlockTemplate* CreateNewBlockWithKey(CReserveKey& reservekey) { CPubKey pubkey; if (!reservekey.GetReservedKey(pubkey)) return NULL; ...
7
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1answer
3k views

Why do miners seem to be using consecutive letters for the Coinbase transaction text?

If you look at coin.dance, it looks like the coinbase transactions text start with consecutive letters. For example, block 478529 starts with "AM" and 478530 starts with "BM" and 478531 starts with "...
7
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1answer
2k views

Where, in the code, in the Satoshi client is 21 million cap implemented?

Which fragment of the Satoshi client is verifying if announced block has a valid reward? I mean, we now live in the 25 BTC reward period. I guess client after receiving a newly minted block, does ...
7
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2answers
2k views

What is the format of coinbase input scripts?

The input script of the coinbase transaction of block number 1 (right after the genesis block) looks like this: 04ffff001d010b How do I recognize this as a coinbase transaction? Do I simply know ...
6
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1answer
2k views

Coinbase transaction's 100-block cooldown period

From the developer guide: The UTXO of a coinbase transaction has the special condition that it cannot be spent (used as an input) for at least 100 blocks. This temporarily prevents a miner from ...
6
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1answer
673 views

Can a miner steal another one's block?

Say we have two miners, Alice (an honest miner), and Eve (an evil miner). My understanding is that when Alice mines a block she advertises it to the network, and once it's part of the longest block ...
6
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1answer
4k views

How to fully decode a coinbase transaction?

After reading this What is the format of the coinbase transaction? I was wondering about a few things. decoderawtransaction of a random Litecoin coinbase transaction: "coinbase" : "...
5
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2answers
3k views

Must a Block contain a coinbase transaction?

Must a block contain a coinbase transaction? If so, how is this enforced?
5
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2answers
929 views

Is there a way to find the coinbase for a given block using only bitcoind commands?

ASICMiner includes hex(Mined By ASICMiner) in the coinbase. I'd like to generate weekly statistics that include ASICMiner' solo-mining efforts, but I don't want to have to rely on blockchain.info or ...
5
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1answer
170 views

Where is the code that sends generated Bitcoins from mining to the wallet?

I was just looking through the Bitcoin code but since I am relatively new to C++ I was wondering, if anybody could tell me where the code responsible for sending coins generated through mining to the ...
5
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6answers
1k views

Possible to do recurring payments with Bitcoin?

I'm a developer and using the Coinbase Ruby API to attempt to build a Coinbase application. I'm still coming to grips with how it all works. My question is, is it possible to set up recurring ...
4
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1answer
2k views

ScriptSig (coinbase) structure of the Genesis Block

From original bitcoin c++ source code: // Genesis Block: // CBlock(hash=000000000019d6, ver=1, hashPrevBlock=00000000000000, hashMerkleRoot=4a5e1e, nTime=1231006505, nBits=1d00ffff, nNonce=...
4
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2answers
331 views

How does the network apply credit for created blocks?

First post. I must say in advance thanks to everyone for all the great conversation and help and software so far. It's really helped me get familiar with bitcoins and bitcoin mining. I have a ...
4
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1answer
918 views

Is it true the genesis block reward can't be spent forever? [duplicate]

Is the genesis block reward forever unspendable?
4
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1answer
1k views

Which receiving address does my block reward go to when mining through bitcoind?

I'm wondering where goes the BTC as my bitcoin server finds a block? Using bitcoind, I see no setting for a bitcoin address..
4
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1answer
156 views

Replay attacks: can a coinbase transaction be replayed?

I'm pretty sure that I understand how replay attacks work: A malicious node takes a valid transaction from chain A, and replays it on chain B. Other nodes on chain B see the transaction as valid and ...
4
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1answer
2k views

Details on Genesis Block

The question asked here displays the genesis block in pretty good detail. I am still trying to get a breakdown of some of the elements seen here (and some others not seen here): The Merkle Root Time ...
3
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1answer
5k views

How is 10% transaction fee possible for a bitcoin transfer from coinbase to another exchange?

I moved 0.01BTC from coinbase to another exchange and i got charged 0.001BTC for it. This is 10%!!. I understand concept of dynamic pricing depending on network crowding etc. However, how is 10% fee ...
3
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1answer
455 views

How does a miner collects the fees?

The way I understand it, at the very top of the block the miner adds a transaction to collect the 25 bitcoins it would earn if it solves the block. Obviously that transaction is included in the hash/...
3
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1answer
29 views

Was it always required for the Coinbase transaction to be the first transaction in a block?

The user tempo mentioned on another topic: "At least in the early protocol versions it was possible to put the coinbase transaction not on the top of the outputs." I have never heard about this ...
3
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1answer
235 views

Why does Bitcoin block 526,591 have a 6.25 (instead of 12.5) block reward?

https://chain.so/block/BTC/0000000000000000002ba5a1fb96f93e6c215d62db4280f1cbd30e82c7c71fba https://blockchair.com/bitcoin/block/526591 It's an empty block (zero transactions), but the coinbase ...
3
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2answers
533 views

Why are coinbase transaction outputs greater than reward?

If the sum of the coinbase transaction's outputs must be less than or equal to the current reward (25 btc currently), why in practice do blocks have a slightly higher coinbase transaction output (for ...
3
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1answer
375 views

Duplicated hash values in mining reward

This transaction is contained in two MainChain-Blocks: https://blockchain.info/tx/e3bf3d07d4b0375638d5f1db5255fe07ba2c4cb067cd81b84ee974b6585fb468 On Blockexplorer there is a note of this anomaly: ...
3
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1answer
68 views

What is the maximum number of bytes the coinbase scriptSig (coinbaseaux) can hold?

Since the scriptSig of the coinbase transaction of a block can contain arbitrary data, what is the maximum number of bytes it can contain? I've seen various mentions of a limit around 100 bytes, but ...
3
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1answer
1k views

How do I create the coinbase from the genesis block?

I wanted to write an application that given a timestamp(text basically) and a public key will generate a merkle hash for the creation of a new genesis block. So I decided to first try and re-create ...
3
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1answer
1k views

Who issues the transaction of reward when a miner solves the block?

I know that when I send money I create a transaction. The transaction is unconfirmed, and then gets confirmed and the address owner gets the money in his wallet by summing up all the transaction of ...
3
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1answer
114 views

Is there any way to get the block number of generation from coinbase?

I was looking on http://blockexplorer.com/ and saw a coinbase of ...
3
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3answers
275 views

How can I find the coinbase transactions where the bitcoins involved in a transaction were created?

I am exploring a transaction and if would like to know when was the money created, I guess I would end up with a lot of coinable transactions. For a certain transaction I could explore the previous ...
3
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1answer
1k views

How can we look at the hidden message in the first block?

This is the first block, how can I see the message? 'The Times 03/Jan/2009 Chancellor on brink of second bailout for banks'
3
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2answers
1k views

How to make genesis block transaction spendable?

I read this question Why can’t the genesis block coinbase be spent? . It says because of some quirk (the genesis block coinbase transaction is not added to the global transaction database) genesis ...
3
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1answer
777 views

How is the encoding of extraNonce done in the genesis block?

You can see here the coinbase of the genesis block txNew.vin[0].scriptSig = CScript() << 486604799 << CBigNum(4) << vector<unsigned char>((const unsigned char*)pszTimestamp, (...
2
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3answers
618 views

How to read the transaction of a block?

Given this example block (it's the genesis block by the way): ...
2
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1answer
12k views

Limit order versus Market order

What is the difference between the two definitions that is not the following explanation: "Sell BTC 2.3 at $593.18" is an example of a limit order asking for $593.18 per 1 BTC. "Buy BTC 0.32 at $592....
2
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1answer
474 views

Has the nonce used in mining been sized?

In the mining process, everytime a block has to be confirmed, a certain hash with an incremental nonce is generated: If the nonce is a 32 bit number it can assume a value between 0 and 2^32 - 1. It ...
2
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1answer
142 views

Why does this coinbase transaction have two op_return outputs?

I've been looking at coinbase transactions for fun and I came across one with two op_return outputs.. Does anyone know what the second one is? Also, I understand the first op_return is used to ...
2
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1answer
44 views

When does miner insert the coinbase transaction?

When a miner creates the candidate block with transactions from the mempool, does he insert the coinbase transaction after winning the PoW or during PoW?
2
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1answer
78 views

Is the reward for successfully mining a block a transaction on the bitcoin network?

If so, what are inputs to that transaction? If not, how are rewards tracked in the network?
2
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1answer
223 views

collecting block reward and transaction fees

i was reading document about transaction data and there seems to be two contradicting paragraphs: Every block must include one or more transactions. The first one of these transactions must be a ...
2
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1answer
524 views

OP_RETURN in a coinbase transaction?

Hey looking at this transaction I'm confused why there are two outputs and why one of them is labelled with OP_RETURN
2
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1answer
63 views

Weird script stack entries at block #227837?

At block 227837 , the coinbase TX e35ca7413b61397a49551fea6ebb540988afcf4a2d0e750773d38eb11b138f40 has the following script: ...
2
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1answer
148 views

What happens to the transaction using the coinbase transaction output of a block later considered stale?

As I understand it, a stale (orphan?) block is determined after it is out competed by its sister block. But I can't help but wonder what would happen to the coinbase transaction's output of the stale ...
2
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1answer
470 views

Where is the source code that allows new coins to be generated?

As per Bitcoin documentation, new coins are generated and brought into circulation when miner receive the reward. I am not talking about existing coins that are collected at the time of mining. Can ...
2
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2answers
474 views

Earliest block with spent coinbase

What is the earliest block in the blockchain that has a spent coinbase? I have manually looked at the first dozen or so but they are all unspent.
2
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1answer
56 views

Can a miner give themselves less than the maximum block subsidy if they wish to do so?

The current maximum block subsidy is 12.5 bitcoin. A mined block recently got rejected from full nodes after a miner tried to post the block subsidy as 13.26 bitcoin. But what about in the other ...