11

bitcoind supports the argument -stopatheight, which takes the number of blocks to download before halting.


5

Blocks have timestamps, but they are not very accurate. The protocol rules only (roughly) require them to not be more than 1 hour in the past and not more than 2 hours in the future. At least historically, miners have used this flexibility, effectively turning part of the timestamp as an additional nonce field. I don't know if this is still common practice. ...


4

The flaw in your thinking is that you assume your transactions will be confirmed. That is not the case. There is no guarantee that a transaction will ever be confirmed, and in fact, if the fee is too low, it is almost guaranteed that the transaction will never confirm. You should care because the person you are sending Bitcoin to cares that it confirms. You ...


4

Once the mining pool has the list of all of the transactions they are including in that block, they calculate the merkle root for this list of transactions, then they distribute the block header, that includes the merkle root, to miners to work on. So, no, it's not constantly being updated, unless for some reason a new transaction was being added or removed ...


4

nBits is a compressed representation of the target value that the block's hash must be less than. Bitcoin does not actually care about difficulty. Difficulty is just for humans to think about how much work is actually being done. Bitcoin only cares about nBits and the target value it represents. A block's hash must be less than that target value. nBits is ...


3

Rabbit holes are deep Bitcoin's blockchain doesn't really know who owns anything. Bitcoins don't exist as things whose ownership can be reassigned. Bitcoins have no individual continuity. Yes the Blockchain effectively keeps track of changes of something that often corresponds to what we think of as ownership of money. However the blockchain cannot ...


3

Full nodes don't even need to store the entire blockchain (bitcoin core has a pruning mode). They must process each block at least once to ensure they have the correct UTXO set, then the raw block data can be discarded.


2

As long as your Bitcoins are in Kraken and you haven't withdrawn them, then the Bitcoins aren't actually recorded on the blockchain -- Kraken just has a line in their database saying they owe you a certain number of Bitcoins. You wouldn't find this on the blockchain until you actually initiate a withdrawal of your Bitcoins from Kraken. Every Bitcoin exchange,...


2

I am new to cryptocurrency development, and I have noticed that Bitcoin has an official wallet for both Desktop and Mobile (correct me if I am wrong). There is no official Bitcoin wallet. My question is, does Bitcoin have an official explorer and value API (such as Bitcoin to fiat conversion) too? There is no official Bitcoin explorer or value API. If ...


2

There are two values in play here, and the way your question is phrased makes me think you're confusing them. Every block has: A hash (computed by double-SHA256 the block header, including timestamp, nonce, version, Merkle root, nBits which encodes the difficulty, and previous block hash) A target (computed from the difficulty only) ...


2

I think you're confusing a few things. A SHA-256 hash is a single value that is 64 hexadecimal characters long. This hash can be seen as simply a very long number. A target hash in cryptocurrencies is the maximum value that a successful block hash should be. Miners are aiming to generate a block where the hash, when seen as a large number, is a smaller ...


2

The comparison used is numeric These are numbers not strings of characters. You can see this by looking at the code in the 2009 main.cpp of the Bitcoin reference implementation: uint256 hashTarget = CBigNum().SetCompact(pblock->nBits).getuint256(); uint256 hash; [...] if (hash <= hashTarget) { ...


2

When fulfilling a trade the BTC seller deposit the coins in a multisig script with 2 keys, one controlled by them and one by the buyer. When the BTC seller acknowledge the reception of the fiat payment, they release the coin to a script only controlled by the buyer. This mechanism, as well as a number of others (see the documentation for details), aims to ...


2

would it be safest to double check Yes but the difference in safety, although not exactly zero, is approximately zero. is it true that when there is a collision of address, both that person's private key and mine can move this bitcoin amount to else where Yes. Statistically that will not happen in any timespan you or I can properly comprehend. See related ...


1

I can't imagine any other reason as to why BDB wasn't dumped altogether if it wasn't for backwards support. There simply is none. The wallet file doesn't need to be a database, it could be a flat text file and that would operate just as well. BDB will remain for compatibility for the foreseeable future, and change is risky, so it remains.


1

Backwards compatibility is a massive priority for Core and it is generally very conservative in its technology choices. I don't think it would consider a new (database) technology until it had been proven over many years on other projects. It is providing a consensus engine and infrastructure and doesn't have the same tolerance as startups or bigger ...


1

No. The Blockchain.com ID is simply a random ID number that points to an encrypted copy of your wallet. Their support will not be able to help you find the addresses or gain access to the wallet even if they wanted to. Unfortunately, if you've lost your password and your recovery key, and you can't find any backup copies of them, you're probably out of luck.


1

Cash The Bitcoin network doesn't authenticate users. The Bitcoin network doesn't know or need to keep track of people's identities. Just as a recipient of a $10 bill or €50 banknote don't need to know the identity of the other person, they just need to examine the paper to see if it looks genuine. Bitcoin is cash, not a bank account. Bitcoin transactions ...


1

You can get an overview of the recent blocks by visiting a "block explorer" such as e.g. blockstream.info or blockchair.com. These usually report the timestamps of blocks as seen in the screenshot below. Note that the timestamps in Bitcoin blocks are picked by the block's author and may diverge from the actual time the block was found. via ...


1

If you can still log into the OLD wallet that has the BTC in it, you could try to set up a New Wallet under a different email address and then pay yourself. It will move the currency you have in that wallet to the new one. You'll have to pay a fee though, unfortunately but if that's the only way to get it back and on a New Wallet where you can access the BTC ...


1

The blockchain only implicitly tracks the existence of each piece of Bitcoin. If you have experience with accounting, the terms "journal" and "ledger" may be familiar. The "transaction journal" is a list of all the transactions that were made in some period of time, for example one business day. At the end of the day, the ...


1

Above answers regarding seedrecover.py and BIP39 are wrong. Blockchain.info legacy wallets can use any number of words from 15 to 21 or more. The number of words changes depending on your password length. The words are NOT a part of the BIP39 seed words and seedrecover.py will NOT be able to find the missing words as it is based on a completly different ...


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