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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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3answers
787 views

By byte size and number of inputs/outputs, what are the largest transactions in the block chain so far?

Disregarding value, but instead going by size in the protocol, what are the largest transactions so far in the history of Bitcoin, in terms of: byte size number of inputs ("vin") number of outputs ("...
2
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2answers
387 views

What is the size of different Bitcoin transaction types?

I found this interesting take on Bitcoin transaction type trends from 2015. As that article is from 2 years ago, I am wondering: a. Are there any newer transaction types? b. What is the average ...
2
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2answers
73 views

API for multiple blockchains

Is there an API to get data for multiple blockchains? Most blockchain explorers already offer an API but I'd like to be able to get information for different blockchains through the same API.
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1answer
23 views

Non-spend Blockchain.com

A bitcoin trader opened a blockchain wallet for me and then sent me my profit but it is non-spendable. I know they can no longer get into my account because I changed the password and I have two-step ...
0
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1answer
22 views

Can can I identify my deposits to a wallet on a BTC (or LTC) blockchain (using the blockcypher api)

I'm trying to reconcile my deposits to a wallet (happens to be LTC) on an exchange account with the data on the blockchain. I was using the logic: if tx_input_n is -1 then transaction is a ...
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1answer
12 views

How to subscribe for blockchain webhook

Please how do I get to subscribe to a BTC address to webhook for unconfirmed transactions?
18
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4answers
5k views

What is the “blockchain”?

What is the blockchain? I keep hearing about other "blockchain technologies", does this mean other cryptocurrencies or what?
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1answer
35 views

Extract sender ID and recipient ID of a bitcoin transaction

I'm new to this world and I'm trying to learn the blockchain world and especially now I've concentrated du bitcoin-core, I would like to parser and get the various information like the various sites ...
0
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0answers
15 views

In the event of pending computer crash that might corrupt my Bitcoin Core blockchain download. What files can I copy to prevent corruption?

I run Bitcoin core on my windows 10 machine. And occasionally the damn thing shuts off all my applications and corrupts my Bitcoin Core blockchain download. Yes, I know, don't use windows. That's the ...
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2answers
30 views

What happens to the transactions included in the forks?

Let: a) the vector triplet <x,y,z> refer <height, index, parent_index> b) blocks, block100, block110 (of height 1) are mined together and they both refer previous block block00[null] (of ...
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2answers
236 views

What is the counterpart of mining when using blockchain for traceability?

Our project is to create a blockchain so that a customer can traceback any registered good (such as food or drugs). The idea is to replace money with product IDs. (ERC721 from Ethereum does not do the ...
0
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1answer
35 views

“Centralized Relational Databases” vs. “Decentralized Blockchain ” : Which one is really more scalable?

There are many research papers on problem of scalability of blockchains: Just as an example : An Overview of Blockchain Technology: Architecture, Consensus, and Future Trends However, (usually by ...
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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 ...
1
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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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0answers
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 ...
4
votes
1answer
899 views

Is there anything called anonymous or private bitcoins?

Are there different types of bitcoins? Is there anything called private or anonymous bitcoin which can not be traced? This question may sound stupid but I am facing this question right now. I have a ...
0
votes
1answer
238 views

can I use elements of the blockchain to protect the integrity of a leaderboard without central servers?

For a World of Warcraft community feature conception contest I've come up with something that involves a leaderboard. However, World of Warcraft addons are purely individual, so a centralize platform ...
1
vote
1answer
67 views

How can you get a list of all addresses mentioned in the blockchain?

I'd like to parse the blockchain in order to produce a list of all addresses that are mentioned in the blockchain. I'd like to do this with a program, language agnostic.
0
votes
1answer
49 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 ...
0
votes
1answer
567 views

Bitcoin transaction graph

I am trying to make bitcoin transaction graph, but I am not sure how to go about it. I have extracted the necessary data from blockchain like the sender, receiver, amount of bitcoins sent, transaction ...
0
votes
2answers
15 views

Blockchain and ISO/OSI

I've heard blockchain is built on top of the ISO/OSI stack. Does it means blockchain belongs to the layer 7 (Application layer) of the Osi architecture?
2
votes
1answer
738 views

bitcoind crashing due to insufficient memory?

EDIT 3 Bumping my VPS to 1GB of physical RAM stopped the crashing issue... UNTIL said VPS ran out of disc space. I added prune=10240 to my ~/.bitcoin/bitcoin.conf file such that the blockchain file ...
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1answer
20 views
0
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1answer
132 views

Use json-rpc without full blockchain

So i want trying to use both bitcoin and bitcoin-abc json-rpc on raspberry pi but they will overload the whole pi when downloading and sync @ same time. So is there anyway to use json-rpc without ...
0
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1answer
36 views

how to achieve transaction info of all the blocks

I use https://chain.api.btc.com/v3/block/date/20151215 to achieve list of blocks and also use https://chain.api.btc.com/v3/tx/0eab89a271380b09987bcee5258fca91f28df4dadcedf892658b9bc261050d96?verbose=3 ...
0
votes
1answer
9 views

How do I move the blockchain file location on windowns?

I tried to edit the storage information on bitcoin.info but neither the windowns 7 nor the Bitcoin qt could do it (it says that the app can't open the configuration file). So I tried to edit in the ...
50
votes
6answers
50k views

What is the Merkle root?

The Bitcoin wiki Vocabulary article explains why the Merkle root exists: Every transaction has a hash associated with it. In a block, all of the transaction hashes in the block are themselves ...
0
votes
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 ...
0
votes
1answer
153 views

How to unblock an account that is held to ransom

I have a blockchain account with bitcoins in but the account is held at ransom. I have to pay 2140$ to get a private key. Is there any way to report this to Blockchain. I did a trading agreement. ...
2
votes
1answer
60 views

What is Sentinel Chain? Is it a cryptocurrency scam?

What is Sentinel Chain? Is it a cryptocurrency scam? Can somebody help me? Thx!!!
0
votes
1answer
105 views

Hypothetical, is it possible to retrieve stolen blockchain currency?

It is my understanding that blockchain technology is decentralized meaning there is no middle man in transactions. This seems like it has benefits but it also has downsides. When necessary, middlemen ...
0
votes
1answer
314 views

Where do I obtain private keys?

Just received my profits from a "watch only" address, where do I obtain private keys?
0
votes
1answer
40 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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votes
0answers
29 views

Is that considered money laundering by Bitcoin in Germany?

Let's say I have 1000 Euro (in German bank account from legal income) because the German bank's interest is 0% so it is not wise to keep money in my bank account. In my home country (3rd world ...
0
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1answer
16 views

Blcokchain corrupt ledger

What happen to the node if we find that node on blockchain has corrupt ledger? Is the ledger sync with other ledger or get discard.
3
votes
3answers
119 views

Whose blockchains are all these ICOs using? Bitcoin's? Ethereum? Are they creating their own?

This is a general blockchain question - not specifically bitcoin. Hoping this is the right place: When a company raises money through an ICO such as Telegram, are they creating their coins and ...
0
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1answer
105 views

How do i get max and circulating supply of a Blockchain? [duplicate]

Hi how do i get the circulating supply for etc Bitcoin, Ethereum and so on? I am not talking about coinmarketcap's API i want to get these data myself. Is there any tutorials on how to do this ...
0
votes
2answers
69 views

Is there an efficient way to get the last 200 blocks (BTC, LTC, ETH)?

I am looking for an efficient way of getting the last 200 blocks and being able to pull all transactions related to an address. I would like to do this for BTC, ETH, and LTC. Is there any way to ...
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vote
4answers
3k views

How do I reverse an unconfirmed transaction to the original wallet

Is there an easy to understand step by step guide I can execute to create a double spend and get the unconfirmed transaction reversed back into the original wallet so I can resend it with a higher fee ...
0
votes
1answer
31 views

How to see download sync speed when syncing the Bitcoin 0.17.1 Blockchain on Ubuntu 18?

I'm syncing the bitcoin 0.17.1 blockchain from the beginning on Ubuntu 18 using Bitcoin Core Qt gui client. Is there a way to see the download speed of the Bitcoin Blockchain and how much time I have ...
0
votes
1answer
64 views

Share private data and prevent data forwarding

Let's say A has some private medical records of patients and B is a pharmaceutical company who wants to view medical records from A to find out the effect of a particular drug on the patients (run a ...
0
votes
1answer
258 views

How mine cloned altcoin new algorithm?

Hi there i will created new clone for practice. Changed algo at cloned one For example nist5 to skein. I created genensis block. Created daemon and qt and nodes are connected. Everything is well to ...
3
votes
1answer
418 views

After downloading the entire Bitcoiin blockchain from a torrent, what are my next steps to link it to Bitcoin Core 0.17.1?

I downloaded the entire bitcoiin blockchain into my external mounted drive as seen below and named the directory bcore. I then did a symlink to that folder like this in my home folder (~) location : ...
1
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2answers
119 views

verified transaction in a block is verfied by one node?

i want to know whether block is a combination of transaction verified by one node so all the transaction in that block is verified and once node is full node will broadcast it or any node can add ...
0
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1answer
38 views

How does bitcoin broadcast information?

On Bitcoin's Blockchain, how is information transmitted instantly to all other nodes and do nodes 'talk to each other' through an API? Do Blockchain nodes communicate with each other through HTTP ...
0
votes
1answer
76 views

Error getting bitcoin block to process from DB

i am installing a full node on a linux server and i'm trying to connect to bitcoin with BIFROST(https://github.com/stellar/go/tree/master/services/bifrost) but i am getting the error below which ...
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0answers
17 views

Reliable nightly download of blockchain data

Is there a reliable night download able blockchain file? The sync is now on its 3rd week. And getting slower. Many cpnfigs tried.
0
votes
1answer
161 views

Can a ZCash shielded/deshielded transaction have values for both vpub_in and vpub_out

As I understand, Zcash shielded and deshielded transactions use a JoinSplit when converting notes from shielded to transparent (and vice versa). vpub_old - is the value that the JoinSplit transfer ...
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0answers
10 views

Hyperledger Blockchain hash function and public-key encryption

I am wondering what is a hash function and public-key encryption that uses to sign any transaction in Hyperledger blockchain platform?