8

There is no requirement that blocks have a timestamp after the previous block. The only requirement is that the timestamp is greater than the median timestamp of the last 11 blocks. So this means that a block can have a lower timestamp than its parent, within a certain bound. This happens because miners do not have perfectly in sync clocks. There can be ...


4

There is a fair amount of leeway in the block timestamp. The timestamp for block N must be greater than the median network time, which is calculated as the median of the past 11 blocks, and also less than the network time + 2 hours, where network time is calculated based on the node's system time, as well as the median time reported by the node's peers.


4

Yea they can still access your wallet. When the scammer created the wallet, they will have written down the mnemonic seed phrase for the wallet. With this seed phrase, they can recreate your wallet using some other software, since the seed phrase will allow them to derive all of the same addresses. They do not need the password to do this, and changing the ...


3

In theory there is one block per 10 minutes. That means you should be able to approximate the time of a block n as FIRST_BLOCK_TIME + n*600, where FIRST_BLOCK_TIME is the time of the genesis block, 1231006505. Of course, that's very approximate, as the average time per block has been consistently less than ten minutes due to increasing block difficulty. In ...


3

If you torrent or otherwise download the blockchain but do not validate the data received, then you will be unable to know whether or not the data received is valid. This means you could easily download a chain which has been altered by an attacker, to include fake transactions, remove legitimate transactions, etc. You would have no way to know. This is ...


3

A modern mining system will do both. Today, miners and mining pools have more hashpower than required to check all iterations of a nonce and extraNonce for a single block template. They get around this by consecutively operating on multiple block templates, usually varying on the block timestamp, data in the Coinbase transaction, and the list of selected ...


2

As soon as the miner finds a solution to the proof of work. This is as soon as they find a combination of transactions and other data for which the hash is less than, or equal to, the current target. Yes, the miner can choose whatever transactions maximise their return. Blocks can contain zero transactions (other than the coinbase transaction which pays the ...


2

Is this wallet.dat with balance some sort of scam or exploit? It looks like a scam. There is never a good reason to buy a wallet.dat. Looking at these videos, you will notice I guess we will notice whatever the video creator tricks us into noticing. As I'm sure you know, making an app that looks like another app is trivial. As is editing video to make ...


2

When a miner have constructed a block (step 1) and is trying to solve the puzzle (step 2), a very attractive transaction with high fee comes, will the miner give up the work he has done, reconstruct the block and restart solving the puzzle? Either that work produced a block or it did not. If it produced a block, he will definitely broadcast that block. If ...


2

The block template is updated, (maybe) every a few seconds, updated with new transactions. will the miner give up the work he has done Every block with a hash satisfying the target is propagated. But if a block wasn't made, remember that mining is a Poisson Process, with the most important property being memoryless-ness. If a block takes 10 minutes on ...


1

Assuming this is a standard P2PKH/P2WPKH address, your wallet will need knowledge of the private key that was used to derive this address, in order to spend the funds locked to it. Addresses are public info, so when you 'import an address' to a wallet, that just means you have instructed the wallet to watch that address, and report back the apparent ...


1

All nodes agree to add another transaction that mints a certain amount of bitcoins to the miner. No, every miner already includes the transaction that pays them in their own block template. Whatever miner succeeds pays themselves by means of their block being the winner. However, I am confused about what protections there are against a bitcoin node ...


1

The transaction would likely not be relayed. Even though a block could theoretically contain such a transaction, nodes would not relay such a large transaction. There is a transaction relay policy where nodes will refuse to accept and relay a transaction that is larger than 100 kb. Furthermore, depending on how this virus is encoded in the transaction, it ...


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