17
votes
Accepted
When Schnorr signatures are part of Bitcoin will it be possible validate each block with only one signature validation?
Yes, one validation per block, but not one signature per block.
To clear up confusion, there are 3 distinct technologies involved here:
(1) non-interactive aggregation is the ability for a third ...
- 110k
14
votes
Accepted
How long does block validation take?
There are several questions here.
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.
Yes and no. ...
- 110k
13
votes
Can someone explain this weird mining activity?
It has no transactions other than the coinbase transaction. However, the transaction's coinbase output is 0 BTC. Here's the valuable piece of information that you are looking for:
Coinbase outputs ...
- 10.2k
13
votes
Accepted
Can a miner just introduce a block full of valid predetermined transactions in the blockchain and get rewarded?
This will not work, because a block's content includes the previous block's hash which means that a valid block can only be mined after the previous block is known.
The dummy transactions would not ...
- 77.9k
12
votes
Accepted
Does assumevalid lower the security of Bitcoin?
which, as I understand it, makes some data (until 2017?) real without verification.
You understand incorrectly. Firstly, the assumevalid blocks is updated at every major release, so it is at most a ...
- 72.2k
11
votes
Accepted
Bitcoin Core - Go back to a specific block?
You can't delete the block data themselves, but you can reset the blockchain state to a specific block by using the invalidateblock command. This command will mark a specific block and its descendants ...
- 72.2k
11
votes
Accepted
Do miners validate each other's blocks?
Mining is a random, progress-free process. Miners are essentially attempting to find a partial pre-image of a hash. Each new (valid) block candidate has exactly the same minuscule chance of yielding a ...
- 77.9k
9
votes
Do miners validate each other's blocks?
But why do miners consent that some other miner managed to mine a valid block before them?
Any miner that is spending resources to find a new block will want to ensure that they are spending those ...
- 18.4k
9
votes
How is a block accepted with one invalid transaction among many valid transactions?
It's not accepted. In a block, every transaction has to be valid by itself, but the whole block has to be valid as well. If anything is wrong about the block, it's simply invalid—there is no "...
- 77.9k
8
votes
How does a blockchain relying on PoW verify that a hash is computed using an algorithm and not made up by a human?
A Hash Function maps "data of arbitrary size to fixed-size values". As an incredibly simple hash, consider a function only works on numbers and simply returns the last 3 (decimal) digits (ie....
- 181
7
votes
How does a blockchain relying on PoW verify that a hash is computed using an algorithm and not made up by a human?
Because
Everyone can quickly use the transaction data to re-calculate the hash and check that it matches and is less than the target value.
Computing the hash is not what takes time, it is altering ...
- 28.5k
7
votes
How many sigops are in the invalid block 783426?
The correct, but non gratifying, answer is 80,003.
I found it by changing MAX_BLOCK_SIGOPS_COST, recompiling and the using the invalidateblock and reconsiderblock RPC to recheck it.
The block fails ...
- 1,034
7
votes
How many sigops are in the invalid block 783426?
The answer is 80,003. I arrived at the same number as Sjors by writing a script that goes through every transaction in a block and counts the sigops.
Here is a detailed breakdown:
Bare multisig ...
- 10.4k
6
votes
Accepted
What forces transactions to be visible to all miners?
A transaction can go in a block if it's valid (references inputs that are already in the same or previous blocks, scripts are legal and return success, and signatures validate ok), regardless of ...
- 23.1k
6
votes
Do miners validate each other's blocks?
But why do miners consent that some other miner managed to mine a valid block before them? Why don't they claim that some other miner's block is invalid even if it actually isn't, and buy time to mine ...
- 51.7k
6
votes
Accepted
Why is there no such thing as a redirected, forged, or fake transaction?
The Bitcoin protocol follows a Unspent Transaction Output system to track the existence and state of all Bitcoin in the system. These are known as UTXOs.
All transactions that transfer Bitcoin do so ...
- 17.3k
6
votes
What prevents miners from inserting fake transactions given SegWit?
If I'm understanding segwit correctly, miners have to verify signatures in order to include a transaction into a block that they are mining. However, miners are not required to verify signatures in ...
- 110k
6
votes
Accepted
Is there a well defined last block?
is there a well defined last block?
I don't know of a specific limit to an exact block height like the well-defined and well-known upper limit to the money supply (<21M).
However, with the current ...
- 28.5k
5
votes
Which sender is banned in case of invalid transactions or blocks?
There is no way to know which node created a transaction or block, unless they publish that information themselves. Nodes should not have an identity that leaks into transaction or block data.
So ...
- 110k
5
votes
How does the node system understand which ledger is the latest before updating their own ledger?
How does a new user realizes which is the correct copy of the ledger to be used when initially updating(downloading) the ledger
They find the highest-work valid blockchain. This is not the same thing ...
- 29.5k
5
votes
Accepted
What happens to rejected transactions (i.e double spend or invalid transactions)?
Invalid transactions are never included in valid blocks. They can be included in a block, but that block would be rejected as invalid (and not classified as an orphan block).
- 72.2k
5
votes
Why can't miners meet the difficulty by picking a low number for the block hash?
The hash is a result of computing two rounds of SHA256 on the block header. If you set the hash yourself, when other nodes try to verify the hash by performing the aforementioned computation, it will ...
- 7,428
5
votes
What stops miners from manipulating "target" difficulty in the block header?
The difficulty target in the block header has to match the currently required difficulty. This value is derived and checked by each node individually from the timestamps and difficulty statements of ...
- 77.9k
5
votes
Accepted
Are blocks containing non-standard transactions relayed through the network or not as in the case of non-standard transactions?
The block will be relayed if it is valid. Standardness rules have no play in a valid mined block.
If it wasn't relayed then the chain would break and that block would probably be reorged out for no ...
- 631
4
votes
Can someone explain this weird mining activity?
Block contains "RSKBLOCK:Ý¿QzßýKÊwQP[9É:
ÔyüN9ÝW³GÆ$", so I think that it is related to www.rsk.co. Probably Sidechains synchronization.
EDIT:
Binary hex: "...
- 253
4
votes
Accepted
Why was my full node knocked off the network last night?
As Nate Eldredge said, the block that you received is a Bitcoin Cash block which is invalid to Bitcoin Core. Because of this, your node banned the Bitcoin Cash node that sent you the block. However, ...
- 72.2k
4
votes
What forces transactions to be visible to all miners?
Whomever originates the transaction (the sender) wants their transaction completed as quickly as possible, especially if they attached a big "incentive" (fee) to it.
So they will announce their ...
- 1,344
4
votes
Accepted
What stops a miner from including arbitrary transactions in their block?
This isn't possible because every node in the network enforces the consensus rules.
A miner is only allowed to include 1 transaction that moves coins with no previous inputs, which is the coinbase ...
- 17.3k
4
votes
Accepted
Incentive for validating block
what is the incentive for the other miners to actually validate that it is correct?
The incentive is to not mine a block on top of something that is invalid. If they do end up mining on top of an ...
- 72.2k
4
votes
Accepted
How are blocks verified?
A block consists of a header, and then a number of serialised transactions. The block header contains no script, it only contains data such as the merkle root of the transactions in the block (so the ...
- 11.9k
Only top scored, non community-wiki answers of a minimum length are eligible