One of the reason wallet force fees is to prevent spam, if they allow customer to send zero fees transaction that have almost no chance of being accepted by miner, their node will be banned (my guess).
In fact you should be careful if you find a wallet that allow you to do zero transaction fees, since they have no incentive to do that it could be a scam ...
valid-fork means that the blocks were fully downloaded and validated. It is likely that they were part of the active chain but were reorganized after a better chain was received.
valid-headers means that the blocks were fully downloaded but not fully validated. Only the headers were validated to have a valid Proof of Work before the block was written to ...
I want to give a comment to this post.
On github exist more parser of BLK file, an example
https://github.com/znort987/blockparser (include the CSV)
I don't have a test these parsers but I think these parsing the correct structure (I don't know the velocity of ...
So can a blockchain can be shutdown by shutting down power supply across the globe? What would happen in such a case?
If the world's power supply was suddenly cut off, then everything electronic would stop working. The blockchain would be 'frozen', each node would retain its local copy, but be unable to communicate with other nodes, and miners would be ...
I maybe wrong but what I think is Blockchain ledger exists as long as there are active nodes in the network. So can a blockchain can be shutdown by shutting down power supply across the globe? What would happen in such a case?
If all the existing power supply suddenly and by magic shut down the ledger would be simply frozen but it would not disappear, it ...
Welcome! I think one important thing to keep in mind is that even under normal circumstances the nodes are not necessarily all "synchronized." In fact overcoming this lack of instantaneous synchronization yet still ensuring eventual agreement on a single history is one of the amazing feats of bitcoin's protocol.
In other words, at any given time node A on ...
I suspect the router in my network prevents the block chain from being sucked into my machine, using the classic way, i.e. bitcoin-qt or bitcoind.
You should check if you can open the 18333 and 18332 port on your router.
Is there a way of dowloading the testnet block chain?
I havent find a direct link to download it but you could do it yourself:
Find a ...
Blockchair allow you to query the bitcoin blockchain with lots of parameter such as date, BTC output amount, fee amount etc...
Here is your request:
Unfortunately it bring no result but you can change the parameters
Increasing the nonce size would not increase or decrease the expected block time.
The block time is maintained via the difficulty adjustment algorithm, which adjusts the network difficulty according to the apparent time it took for the last 2016 blocks to be found. How quickly blocks are found can thus be used to estimate how many hashes/second the ...
This is most likely a scam! there have been a similar question recently Why do I have to deposit BTC as missing turnover
There is no need to send bitcoin or money to receive a private key or unlock a bitcoin wallet, be careful.
Blockchain Explorer says received but it's not received yet!
That's not how Bitcoin works.
All computer-based wallets, including your friend's, have a copy of the blockchain (or have indirect access to a copy). If the blockchain includes your transaction, then the money has been received. All copies of the blockchain are eventually identical, only the last ...
The transaction is confirmed. Make sure that you have sent to the correct address (your friend's address 37ZyDkjmMEkTVjeuLcjH3p5AQEZF5tpr1E).
If you are sure then your friend is trying to scam you because in transaction https://blockstream.info/tx/cb2b8b9fe545ba2705f9831e33417cdf3c4c749eb738cb359d3c3af4834b2768 the UTXO you sent to your friend has been ...
Something that is very similar to what you describe is the concept of "Uncle Blocks" used in Ethereum. Even there, though, there are no partial blocks and nobody would continue to mine on a "half-finished" block. Ethereum has significantly shorter block intervals which causes multiple blocks at the same height to be found often and allowing to reference them ...
You can't be sure that there is not a longer chain somewhere else, since someone could work on another chain without telling anyone about it. It just becomes increasingly unlikely the more confirmations your transaction has.
Building a chain longer than the best chain would require someone to have more Proof of Work hashpower than 51% or more of the total Bitcoin network hashpower.
The unlikelihood of this happening is the guarantee that the longest chain is the best chain.
To build a one block longer chain you'd have to assemble a block and find a nonce that produces a ...
Bitcoin does not work on an account model but operates on an UTXO (unspent transaction output) model. When you send bitcoins to an address, what you are essentially doing is locking those bitcoins in a mathematical equation. Spending those coins requires that you provide the correct unlocking condition (most often signature and public key associated with ...
The easiest way is to use my simple python script (blockchain parser) that can parse whole raw data from the blk*****.dat files into the human readable text view. This script is very simple to understand and it would be the best way to find out what hiding behind the blockchain database.
size refers to the size of the block, which is 80 bytes for the header + sum(tx_sizes). As pointed out in the comments, this includes the segwit data and is meant to match the actual, on disk size of the block.
bits refers to nBits, which encodes the target difficulty for the block. You can see an explanation of the encoding scheme here.
I don't think this is possible; you'd have multiple node instances trying to read/write a single data directory. This is not the intended operation, you'd likely end up with corrupt data.
If you must run multiple independent nodes and are worried about storage requirements, I'd recommend looking into 'pruning mode', it will limit the storage requirements ...
In general, there's no way to know if that address belongs to an exchange.
This is especially true when the funds have not been moved/spent.
Tracking the wallet owner of stolen bitcoins
How can I confirm to whom the bitcoin address I sent a payment too?
In the original source code there were little restrictions on what could be in the coinbase data of the coinbase transaction. I think the only restriction was that the coinbase data should be between 2 to 100 bytes. However, this lack of restriction on what can be within the coinbase data brought up a vulnerability. It was perfectly legal for miners to ...
You have to divide this question into two parts. Your confusion arises from the fact that there is no account per person like a bankaccount.
1 - If there is no account where does the knowledge of who owns how many bitcoin comes from?
The blockchain contains of information about amounts of bitcoins that have been sent to addresses. So, it knows how many ...
How is the monetary aspect of a bitcoin stored?
There is no such thing as a Bitcoin in normal Bitcoin usage. Bitcoin is a currency but it does not have the equivalent of a physical coin that passes around. Bitcoin is really a unit of measure not a coin or anything much like a coin.
Where the monetary aspect is stored depends on where you look.
Within the Bitcoin protocol, each Bitcoin is represented as 100000000 satoshis. Therefore, you can divide bitcoin up with a precision of 0.00000001.
In a transaction, the number of satoshis being delivered to each output is recorded, along with a record of which previous output is being spent.
The fee is then derived from sum(Inputs) - sum(Outputs). The ...
This means you have to wait until the transaction has 3 confirmations before you can use it on Paxful. The time needed for each confirmation is random, but averages about 10 minutes.
By the time you read this, your transaction probably will have 3 confirmations.
If after several hours it still says 0/3, then go and read Why is my transaction not getting ...
If I go back to block #1000 and add one more transaction, this will change the hash and it wont be the same one stored in #1001. However, how the hash of block #1000 changes in the first place if it was already calculated?
Once a block has been mined and accepted as part of the longest valid chain (ie, several confirmations deep), it will not ever change (...
Hashes don't actually 'change'. When you add a transaction to a block you are creating another block.
It's like an author published a book and then next year printed a new edition with an extra comma in the page 36 and the fans said he released a 'new' book. It doesn't make sense for books but for blockchain every bit counts.
To take the information of the bitcoin blockchain, you can use the bitcoin core RPC Framework, for use it, you must have all blockchain on your computer
Download Bitcoin core
aligns the bitcoin node
Configure rpc framework
Use the API to take the information, I prefer using this library with python, this is an example for using it
You can use this ...
The best pdf about bitcoins would be the original white paper by Satoshi Nakamoto https://bitcoin.org/bitcoin.pdf
For programming free ressources I invite you there: https://www.lopp.net/bitcoin-information/developer-tools.html
Then you have some great book like "mastering bitcoin" or "programming bitcoin"
There is no way to directly retrieve your fund since they are the one now owning your coins, maybe try to contact their support directly on their social network like twitter to accelerate https://twitter.com/coinbase