3

Signatures and pubkeys are needed in order to verify transactions after the fact. Miners are not the only verifiers, and just because a transaction is in a block does not mean it is automatically valid. Other full nodes still need to verify all blocks, and that includes verifying all of the transaction in the blocks, which means verifying signatures.


3

Exchanges interact with the Bitcoin network, and the blockchain, whenever people deposit on them, or withdraw BTC from them. You can think of exchanges as services which are effectively like a bank account for multiple currencies. For example, they may offer a USD account and a BTC account. And they let you: Deposit or withdraw USD (using wire transfers or ...


3

There is a risk that the blockchain will continue to grow too quickly and become unwieldy, yes. However, if technology improvements continue at their current pace for several decades, and Bitcoin survives the intermediate turmoil, it will eventually start to get easier to run a node again. "Chopping off some portion" significantly changes the ...


2

There is no need to truncate it. You can just start Bitcoin Core with the -reindex option. If you do, it'll throw away the UTXO set and other databases, and rebuild it from the blocks you have on disk (which will be kept), up to the point where they're corrupt. It'll take a while (possibly nearly as long as synchronizing in the first place), but it won't ...


2

As an alternative to syncing a full Bitcoin node, there is a BigQuery public dataset for Bitcoin (and some other cryptocurrencies): SELECT `number`, `hash` FROM `bigquery-public-data.crypto_bitcoin.blocks` ORDER BY `hash` LIMIT 10 Results in JSON: [ { "number": "634842", "hash": "...


2

But, they are competing with each other and really busy I guess. Here is my question. How much time do miners spend validation in general and start mining? None at all. While they are validating new information, they are continuing to build blocks based upon the older information. Miners do not have any reason to wait to start mining except on their very ...


1

For Bitcoin you can get the total supply via gettxoutsetinfo, which produces the following output: $ bitcoin-cli gettxoutsetinfo { "height": 705603, "bestblock": "0000000000000000000173b87bcaa99c5020eb16b13a856f7015130889c5ff93", "transactions": 45865084, "txouts": 75262497, "bogosize": ...


1

Imagine there are two collision blocks A and B. These are mined at the same time. If both miners are neutral, the set of transactions in A is similar to the set of transactions in B. One miner created new block C on top of block A and longest chain happened. If the third miner is neutral too, it is likely that some transactions in B not in A are in C. And ...


1

what is the difference between: bitcoin-cli getblocktemplate '{"rules": ["segwit"]}' This implements the GBT protocol, specified in BIP21, for letting mining hardware and (in practice, mostly) pool software communicate with Bitcoin Core. It outsources the mining computation to software/hardware external to Bitcoin Core. It is the only ...


1

First of all let's get a few misconceptions out of the way: I was guessing that miners need to validate manually. Like, go to the Blockchain.com and check the last block and unconfirmed transactions and check by themselves, manually. So, I was imagining that it takes 3 or 4 minutes for them. No, miners run full node software, just like you can run yourself,...


1

A few things would happen: The new block would be invalid because it doesnt start with 8 zeros Even if the bad person managed to mine the new block all the other nodes wont accept it because all the blocks after it would be invalidated and it would no longer be the longer chain, the chain would be 4 blocks long but all the other nodes would have a 10 blocks ...


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