Collects questions regarding the validity of blocks according to consensus rules.
Questions tagged [block-validity]
71 questions
14
votes
2 answers
Can someone explain this weird mining activity?
I can't figure why this block has 0 coinbase with 0 transactions... however still a valid block? Or it it empty? According to whalepanda this coinbase was sacrificed by unknown miner.
See the block at height
501,726
user380208
- 613
- 1
- 6
- 11
12
votes
2 answers
Two blocks, two transactions, same hash
Would a block containing a transaction with an identical hash as a previous transaction be considered valid? That is, if someone made a transaction for generating Bitcoins and solve two blocks with the same coinbase transaction, would the second…
ThePiachu
- 42,931
- 25
- 138
- 347
11
votes
1 answer
When Schnorr signatures are part of Bitcoin will it be possible validate each block with only one signature validation?
In a recent talk Pieter Wuille talked about speed up verification when using Schnorr signatures and various algorithms for verifying multiple signatures.
Would it really be possible to verify one single block by aggregating the keys and signatures…
Rene Pickhardt
- 11,670
- 8
- 35
8
votes
1 answer
Why is there no such thing as a redirected, forged, or fake transaction?
In the past, we had numerous questions about "fake" or "forged" transactions. Such transactions could supposedly be created even without holding any bitcoins, yet would end up in the mempool or even get accepted by the network once they are mined…
Murch
- 71,155
- 33
- 180
- 600
8
votes
2 answers
Does assumevalid lower the security of Bitcoin?
Bitcoin's assumption was to download the blocks and verify it in order to prevent getting fooled.
But by default, the assumevalid option is enabled in the software, which, as I understand it, makes some data (until 2017?) real without…
fervi
- 103
- 4
8
votes
3 answers
How long does block validation take?
Assume a miner receives a new block from a connected peer. Please correct me if I'm wrong: The miner validates the newly received block before using it themself and sending it to their other connected peers. I heard this but it seems to me that it'd…
UTF-8
- 3,214
- 1
- 14
- 28
8
votes
3 answers
How many sigops are in the invalid block 783426?
On April 1st 2023 F2Pool mined block 00000000000000000002ec935e245f8ae70fc68cc828f05bf4cfa002668599e4 (full block) which my node failed with bad-blk-sigops.
Bitcoin Core stops counting as soon as it reaches the 80,000 limit.
I had a hard time…
Sjors Provoost
- 858
- 6
- 16
6
votes
9 answers
How does a blockchain relying on PoW verify that a hash is computed using an algorithm and not made up by a human?
How does a blockchain verify that the hash provided (the one with the leading zeros that is supposed to be unique, computed using lots of processing power) is indeed unique and that it wasn't just a random number some one came up with and then just…
Sprout Coder
- 167
- 6
5
votes
4 answers
Do miners validate each other's blocks?
I understand that to mine a block, miners solve a cryptographic problem and the solution can be easily verified by other nodes on the network, appending the new block to their blockchain.
But why do miners consent that some other miner managed to…
flair91023
- 53
- 1
- 4
5
votes
2 answers
How are blocks verified?
I see in the bitcoin wiki there is something called "script" which compiles down to some bytecode to be run by a very very basic virtual machine.
Does this mean that each block is actually just a string/array of bytes when it comes in and is…
Shazzad Kabir
- 65
- 4
5
votes
3 answers
Why do miners validate transactions?
It seems that if most transactions are valid, a miner could save a little time and increase its chance of mining a block by not validating. Is the reason that there are enough invalid transactions to make this an ineffective strategy, because the…
MRP
- 51
- 1
5
votes
2 answers
Why is two hours the maximum acceptable offset for Bitcoin blocks?
As far as I understand, Bitcoin transactions include a timestamp, but the only requirement is that they don't differ for more than two hours.
But why two hours? For computers that are constantly synced via NTP, two hours seem like a very big…
Arturo Torres Sánchez
- 772
- 1
- 5
- 16
4
votes
1 answer
What stops miners from manipulating "target" difficulty in the block header?
I am relatively new to understanding the fundamentals of the Bitcoin network, and I couldn't find the answer to my question.
I understand how mining difficulty/target is decided and calculated in the block header. (hashrate of previous 2015…
Danny I-Tan Lin
- 41
- 1
4
votes
1 answer
At what block height may locktimed transactions get included?
Transactions with outputs whose sequence is smaller than UINT_MAX are interpreted as locked until the timestamp or block height specified in nLockTime is reached.
Specifically regarding the block height, I read imprecise or disagreeing information…
Murch
- 71,155
- 33
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- 600
4
votes
2 answers
What happen if some blocks are added simultaneously with same previous hash
In all of the blockchain samples that I see
e.g.
adilmoujahid,
Savjee
as I checked, they added previous Hash by creating a block.
Suppose that, L is the current last block in a chain. Block A and B are created at the same time. So they set their…
masoud2011
- 141
- 6