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Questions tagged [blockchain]

This tag should be used for questions pertaining to the blockchain. The blockchain is a list of all transactions that have occurred using the Bitcoin currency. It consists of blocks which are linked to each other, and each block consists of transactions. DON'T USE THIS FOR THE SERVICE NAMED 'blockchain.info'!

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What happens to a node if .bitcoin/chainstate is corrupted?

I tried to search for answers to my questions, but didn't find any, but please forgive me if this is a duplicate question. Suppose somehow .bitcoin/chainstate gets corrupted, e.g., a UTXO is deleted. ...
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1answer
25 views

Does a transaction always get verified/processed by ALL full nodes in the network before being added into the block by some mining node(s)?

If not, then why is it often claimed that the blockchain scaling issue is due to the fact that all tx has to be verified by all full nodes? As long as a mining node found the correct nonce, the tx ...
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1answer
24 views

Number of main chain in a blockchain network

I just have a very basic doubt. Suppose there's a public blockchain network like Bitcoin comprising several nodes. Would it be possible that this network consists of multiple mainchains??I am not ...
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30 views

How does the bitcoin network remove duplicate blocks being generated by multiple miners?

Say there are two minersA&B and each of them have produced the next block almost at the same instant. In this situation how is the network going to decide which one is the main block and abandon ...
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1answer
98 views

Converting xpub key to core format

I am experiencing some major issues which I honestly can't understand. When I am generating a wallet from Electrum the public key looks like this: ...
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1answer
34 views

How are transaction fees collected in Bitcoin? [duplicate]

I'm looking into the structure of blocks in the Bitcoin blockchain, and I can't figure out when\how the fees collected by miner of the blocks are transferred to the miner. According to what I can tell ...
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1answer
8 views

Is it required to broadcast the addresses generated locally to the bitcoin network?

Like the transactions are broadcasted to the bitcoin network , is it required that locally generated addresses also need to be boradcasted to the bitcoin network ?
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1answer
25 views

Transaction is not Picked

I am new to block chain technology. I am struggling to understand below concepts: What if my transaction is not picked by the miners and what is the criteria for miners to pick? How can I rely on ...
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0answers
42 views

Which “Hyperledger Project” is more adaptable to be run on “micro-controller”?

Hyperledger has 5 different blockchains: (1) Hyperledger Fabric (2) Hyperledger Burrow (3) Hyperledger Indy (4) Hyperledger Iroha (5) Hyperledger Sawtooth Regarding the fact that micro-...
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1answer
83 views

Where are new addresses stored?

When a user generates an address using Bitcoin Core, is that address by default stored on the blockchain or will it only be stored after it is used in a transactions
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1answer
27 views

Explanation of Blockchain Payment systems [closed]

Trying as much as possible to understand what Blockchain technology is (As i am trying to see if i can be a Blockhain developer) and I just worked on a money transfer system myself and i hear everyone ...
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1answer
42 views

Unknown btc transaction

Could someone please explain what is this second transaction from the wallet 34UuFs8BtnbeJtdM9p4NBCHiP8MaD4f86n ? https://www.blockchain.com/btc/address/34UuFs8BtnbeJtdM9p4NBCHiP8MaD4f86n?filter=6 I ...
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0answers
39 views

Natural Language Processing and Blockchain?

This question is about one of the applications of the Blockchain in Artificial Intelligence. I am not very familiar with Natural Language Processing and I see that there is a Blockchain platform ...
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1answer
76 views

What is the network topology used at the physical layer of the Bitcoin network?

I want to know about the performance of the Bitcoin Network under various network topology and for which it performs the best. Also what is the current topology being used?
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1answer
37 views

Is this calculation of mining probability using the Bernoulli trial formula accurate?

I'm trying to understand the formulas for successfully mining a block (without a pool) based on hashrate over time (i.e. to chart the probability of finding a block at various historical points ...
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1answer
21 views

Why is a blockchain often compared to a linked list?

I often hear people say that a blockchain is essentially a linked list (i.e. https://www.quora.com/Is-a-blockchain-essentially-a-linked-list) A block stores the hash of the previous block for ...
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1answer
38 views

i have lost 83$ worth bitcoin from my blockchain wallet can any one help me to recover it? [closed]

on 2018 oct 19 there was a transaction which I haven't done from my wallet of 83$ bitcoin please help me to get it back
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1answer
70 views

I invested in bitcoin mining. Is this legit?

I invested 250.00 I was told by a miner I could make 3200.00 in profit . Once my profits were shown on blockchain, it read non spendable. I asked what it meant and he said I'd have to invest 500.00 ...
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1answer
34 views

I'm confused about some aspects of bitcoin Lightning network

Theoretically, I know How this network works. but technically I am confused. Is lightning running on the bitcoin protocol or another blockchain? Is is something like Sidechain? Where bitcoins in ...
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1answer
37 views

Is it posible to create a transaction output that can either be reddemed by privK of Addr A or by privK of Addr B AFTER certain blockheight?

I am thinking about how to secure your Bitcoin savings. One idea I had was to create sort of a "backup" address B for an address A which stores the bitcoins. So what I want to achieve is that you ...
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1answer
121 views

How to recover bitcoins from personal wallet app in android which is uninstalled?

I am using a bitcoin Non-deterministic wallet created by a private firm. In which there are few bitcoins worth 100$ Somehow I clear data of the android App, and Now all the memories related to my ...
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1answer
43 views

Is it safe to store user's secure pass-code in database with encrypted form while creating bitcoin wallet?

I would like to create a Bitcoin Wallet. Part of the process is to store public and private keys in encrypted form in server database. All keys I am storing is encrypted using user's passcode. 1) ...
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1answer
24 views

Why lightweight nodes are less secure?

as you know there is two main type of wallets: full node and light node I've read in some advice that just using full node for more security stuff and the next question is what is the type of ...
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1answer
20 views

In the basic Wallet based in QT, How can i get by RPC the stored addresses and labels?

this question is for you to ask about the QT wallet, in the section to send coins, there is an address window, and it has the list of the stored addresses we save along the time. So using RPC, do you ...
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2answers
28 views

Blockchain and anonymous data inside the chain [duplicate]

A Blockchain is often said to be a log of all transactions that were ever verified on a network. I understand that therefore a purpose could be to make sure that the records are not altered. If they ...
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0answers
29 views

UTXO are not being listed while they have conf over 100 (btcd + simnet)

I am using BTCD and while in Simnet, I generated 104 block (Best block : 104) But when I listed utxos, transaction from block 3 and 4 (which have 102 and 101 confirmations) don't be listed. So balance ...
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0answers
97 views

Idioms of use/ bitcoin heuristic

I already know the answer of a) part which is Alice. Can anybody help me in finding answer of b) part.
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0answers
20 views

Failing to create a new address to be used for receiving staking rewards whenever a generated block is accepted

Our problem is that we need to get a new address on each stake. What I've tried so far is: Generating a new address right before a block is accepted and try using it to receive the stakes, but that ...
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1answer
29 views

What is single member blockchain?

I just heard about single member blockchains like quorum and hyperledger-fabric. So what does single member mean? Is this some kind of restriction or what?
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0answers
25 views

Rules of the mining pools for mining software and weight blockchain Litecoin [closed]

What rules must a mining software fulfill in order for a pool to allow mining with the ?, example of a pool please. How heavy is Liteco's chain of blocks at this moment or where can I consult it?
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1answer
27 views

How to get my bit coin back

I have copied and sent bitcoin to the address that I have found on my blockchain wallet only to find out its not mine. So is there anyway I can get my bitcoin back?
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0answers
78 views

Blockchain testnet Websocket

Please, how do I subscribe to blockchain testnet web-socket for an address. I seem to find that for livenet, any help?
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1answer
39 views

Question Regarding Send_to_many function of blockchain wallet api

I am using send to many function of blockchain wallet api and i am facing issue. when upto 20 transaction done then after i get error in terminal that 1538652825520 - error: ERR_PUSHTX ...
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0answers
71 views

Becoming Bitcoin wallet provider from scratch [closed]

I want to launch a bitcoin wallet service website for creating new wallets. And i want to provide a tool for user for importing their old wallets using public and private key. I know i can use some ...
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0answers
12 views

Transactions Uniqueness Verification

From what I gathered, to process a bitcoin transaction I basically create the transaction object locally, add my signature generated with my private key, then send this to a public node for it to add ...
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1answer
41 views

Solar Flare wipes all hard drives… What happens?

Imagine, for a moment, that a massive solar flare wipes out all hard drives on planet Earth. All hard drives are wiped clean and with them all records of the Bitcoin blockchain. Would we be able to ...
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1answer
29 views

Is it secure to collect common public addresses under a wallet using BlockCypher Wallet API

I am working on an exchange platform with users having separate pair of public and private keys using blockcypher api. I encountered Blockcypher Wallet API, and it seems its a pleasant way of ...
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1answer
33 views

Transaction in orphaned block question

This is a theoretical question. Assuming that a transaction (TX_A) with me on the receiving end gets added to the blockchain, I should be able to spend the amount I received. So I go on and spend it ...
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0answers
23 views

What is required to list market data from cryptocurrency? [closed]

I am trying to create a cryptocurrency market capitalization list similar to coinchangelly.com . Where could I obtain their APIs and how do I list much more coins than others?
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1answer
41 views

When does a blockchain fork resolution happen?

I understand that the forks are resolved by largest proof-of-work etc. but when do the miners decide to resolve a fork? Is it a network consensus or do each individual miner resolve at their own pace?
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1answer
40 views

Bitcoin protocol allows a chain to be undone by a longer chain

In Mastering Bitcoin, page 196, it says "While the protocol always allows a chain to be undone by a longer chain and while the possibility of any block being reversed always exists, the probability of ...
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1answer
18 views

Permissioned blockchains on EVM: are these private ledgers os it all on ETH main net?

Private blockchains using EVM: is this really the equivalent of the library of tools in hyper ledger or do these blockchains run on the public main net?
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1answer
50 views

Create wallet address on user registration for trading platform

I am creating a crypto-trading platform . I wanted to know how to create wallet address dynamically for all new registered user and also create new address for every transaction. I am using bitcoind ...
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2answers
45 views

is every Block of blockchain is connect to each other? [duplicate]

like as we create a new block , so it will connected to existing Blockchain or it will create a new blockchain?
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0answers
17 views

Setting up node, no connection when announce ip address to peers

I want to announce my host name when running node. When I set nxt.myAddress=hostname or IPaddress, there are no connection to peers. But when I keep it empty everything is fine.
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0answers
23 views

Leader election-based Blockchains public?

Consensus protocols such as those of Tendermint, Red Belly Blockchain or Algorand can be of great help when dealing with the problem of Finney attacks, and similar sorts of abusing of excessive 'thing'...
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1answer
146 views

Is PBFT a consensus algorithm?

Can we consider PBFT (Practical Byzantine Fault Tolerance) as a consensus algorithm ? And if yes, How does it work? And is it similar to other consensuses such as PoW, PoS or PoA ? Or it is totally ...
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1answer
35 views

Block Chain length/size may one day get unwieldy to compute

Is it possible that the length of the existing block chain will one day become unwieldy to compute? Would it make more sense that the chain would somehow be rolled up like normal bank ledgers do with ...
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1answer
37 views

IBM Blockchain platform specifications

So I saw an ad for IBM's blockchain platform, specifically the campaign they have to "turn plastic into money" by way of exchanging recyclable materials for digital tokens. I was just wondering if ...
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1answer
18 views

Why the block's order in blockxxxxx.dat is different from blockchain.info

I parsed the block00000.dat using python code: class BlockFile: def __init__(self, block_filename): self.block_filename = block_filename self.blockchain = open(block_filename, 'rb', ...