The blockchain is a list of all transactions that have occurred using the Bitcoin currency. DON'T USE THIS FOR THE SERVICE NAMED 'blockchain.info'!

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2
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529 views

Blockchain over 36GB and causing disk space issues

I want to install the bitcoind daemon on a computer with relatively little free space (about 35GB available). I thought that the blockchain was some 20 GB in size and figured that would be no problem, ...
0
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1answer
83 views

Call function for block n on blockchain

I've been going through main.cpp in order to roughly find out which function calls the best block and I found out depending on situation there are several similar-sounding function names and code ...
-1
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1answer
57 views

“Array& params”: How to understand “&” after “Array” - type modifer?

I'm trying to understand how "invalidateblock"-function works, literally line by line. Since I'm at basic level in C++, I couldn't explain to myself what's the "&" after "Array" there to achieve ...
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0answers
59 views

Blockchain API - Returns “Read timed out” when calling my website callback

I'm receiving payments using Blockchain API. The receiving payment part works but after that, when it's supposed to call a link on my website to inform about the payment, it's not working. I'm using ...
0
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2answers
183 views

I run bitcoind in linux centos server. but it give me error “sendto: Operation not permitted”. why?

root@srv [~/public_html/server/bin]# ./bitcoind -daemon Bitcoin server starting root@srv [~/public_html/server/bin]# sendto: Operation not permitted What is the problem? Also, bitcoind didn't ...
4
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2answers
98 views

Valid fork in regtest - Change blockchain via RPC?

I've created a regtest network consisting of 2 nodes - node0 & node1. I'd like to have a fork on the common blockchain and seemingly achieved it by doing so: nodes start node0 adds node1 via ...
1
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1answer
313 views

All Bitcoin Public Keys with non-zero balance

I want to get a database or otherwise retrieve a set off all bitcoin public keys (not addresses) that have non zero balances. What would be the easiest way to do that? Is there an API that could do ...
-1
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2answers
159 views

Is it time to move data storage (of things like music, images, virus definitions) out of the block chain?

This is a technical question and I don't have the answer. I would like someone to explain why this data is necessary. If your answer is receipts or smart contracts, then my question is, "Why not put ...
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2answers
100 views

How is a blockchain split resolved?

Let's say two miners created 2 different blocks and broadcast them into the network. Now some clients see blockchain 1 and other blockchain 2 which are different from each other. I would like to ...
3
votes
1answer
102 views

Parameters in UpdateTip - calculation of log2_work

I looked up log2_work inside main.cpp and I can't follow its calculation by log(chainActive.Tip()->nChainWork.getdouble())/log(2.0). a) What is -> explicitely indicating? (I'm at basic level of ...
0
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0answers
65 views

How to start https and http call according to enviornments

I am using insight api's for block chain. I have installed an ssl certificate for secure connection. In development mode, all calls should be http; in production mode, all calls should in https. There ...
0
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2answers
551 views

Alternatives to OP_RETURN to store data in Bitcoin blockchain

I am working on iOS camera app and would like to store hash of photos inside blockchain for the "proof of existence". AFAIK transaction with OP_RETURN in output has some disadvantages ...
2
votes
2answers
166 views

How to check BTC transaction when buying face to face?

I have never bought bitcoins face to face. Don't have iphone/ipad and therefore I would need answers on the following question: What do I need to have on my cell phone in order to provide seller my ...
0
votes
1answer
64 views

Regtest: One node nullifying other node's balance

I'm running 2 bitcoind servers on the same machine, called node0 and node1. In the following I'm listing steps I take and results I get and I'm wondering what is causing one node nullifying other ...
1
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2answers
312 views

Calculating “total received” and balance by an address

This is something which I think should be simple but it's driving me crazy. See for example this list of transactions associated with an address: ...
2
votes
2answers
295 views

Best way to update an outdated blockchain

I have a relatively slow computer and a slow internet connection. For this reason, I only open the bitcoin client when I really have to (because it uses a whole lot of bandwidth and CPU to download ...
1
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0answers
73 views

How to check Bitcoind block chain download progress level without blockchain explorer?

so my problem isn't with bitcoin particularly but with a dying altcoin, I have the same problem as here. But can't use a blockchain explorer site, since there doesn't exist one. Is there any way to ...
0
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0answers
14 views

When all bitcoins have been mined, how can the Block Chain's interaction be supported? [duplicate]

I've understood for a while that bitcoin mining was a process that required computers to solve increasingly difficult problems in order to mine a block. It wasn't until now that I realized those ...
4
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3answers
331 views

Using Bitcoin or another Altcoin for Decentralized Database Storage

I was wondering has there been any attempts on using the blockchain as a decentralized database storage system? Would it be feasible to use it on Bitcoin or another Altcoin and if so which altcoin ...
1
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1answer
172 views

Bitcoin database needs to rebuild every time after defrag or reboot

I'm running Windows 10 technical preview 10049 and I'm running bitcoin-qt from my data hard drive with 1.17TB available disk space. It is a striped volume and due to much data writing and deleting it ...
4
votes
2answers
203 views

How can services that use the bitcoin blockchain help secure it?

There are many projects being worked on that involve using the bitcoin blockchain for its public verifiability and immutability. A few examples would be Counterparty, Medici, Factom, etc. But each use ...
2
votes
1answer
160 views

Why do some outputs have a zero value and no address?

What does it mean when an output has a value of zero and no address? I'm looking at some fairly recent transactions, and I don't understand what this means. Here's an example: ...
0
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0answers
19 views

What happens when the Block Reward of a Currency is Changed to a Greater Value? [duplicate]

What Happens if the Reward for block solving is changed to a very great extent and if most / all of the users update to that version with the edit.. For example if block reward is 12 x and it is ...
2
votes
2answers
166 views

How does “headers first” effect BLKxxxx.dat structure?

Assuming a full node running Bitcoincore v0.10 (with txindex=1), how exactly does the new "headers first" functionality affect the structure of the blockchain data? (Specifically, the blkxxxx.dat ...
2
votes
1answer
84 views

Bitcoin transactions over Ripple Network

I am interested in using the ripple network in conjunction with bitcoin transactions, but am curious as to interplay between the ripple ledger verification and the bitcoin blockchain verification. I ...
1
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2answers
137 views

Can coin wallets create their own network/blockchain?

In other words, I want a coin with NO premine and NO mining. Can the wallet, alone, generate the coin(s) and the blockchain, based solely on inter-wallet communication (establishing a wallet ...
4
votes
2answers
101 views

Is there a special name for the block currently at the head of the chain?

Just as we have the genesis block which is block 0, is there a special name for the block currently at the head of the chain? Obviously such a block would be observer dependent and never absolute but ...
2
votes
1answer
157 views

Blockchain parser for transaction level details

I'm looking for transaction level data for both inputs and outputs. The znort block parser returns the type of data I'm looking for, however it doesn't seem to detect multisig transactions. Has anyone ...
0
votes
2answers
366 views

Create alternative blockchain with proof-of-work

For learning purposes, I want to create an alternative special-purpose blockchain. It would use a proof-of-work function that is different than the one in Bitcoin. Short of forking bitcoin and going ...
3
votes
1answer
143 views

Live Blockchain Backup

What is a good strategy for backing up bitcoind's blockchain files (not its wallet file) without having to take (e.g.) a bitcoind that is powering a counterparty-server instance offline? Copying the ...
0
votes
1answer
435 views

How to generate a private key to create wallet through api in Block chain

I need to pass private key while creating a wallet in blockchain.info through api call which is defined here https://blockchain.info/api/create_wallet I'm using php for creating wallets. Please ...
1
vote
1answer
395 views

What is the estimated size of complete blockchain when all bitcoins are mined. i.e around 2140?

By size, I mean how many GBs or TBs of data storage I would need to save entire blockchain starting from Genesis block when all bitcoins are mined?
2
votes
3answers
652 views

How to store blockchain data

If I wanted to imprint the blockchain data on a database, with the purpose of performing complex or just different than the RPC-based queries, how would I do it? Would I have to go for a relational ...
3
votes
1answer
95 views

blockchain.info and blockexplorer.com show different balance for the same address

Does blockexplorer.com have a bug or some other reason? https://blockexplorer.com/q/getreceivedbyaddress/1KWd23GZ4BmTMo9zcsUZXpWP4M8hmxZwRU 1.95331249 ...
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0answers
45 views

Blockchain (lack of backwards) compatibility in Bitcoincore 0.10.x

From Bitcoincore release notes: Because release 0.10.0 makes use of headers-first synchronization and parallel block download (see further), the block files and databases are not ...
0
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0answers
118 views

Blockchain.info RPC API and deposit/withdraw problem

I'm using blockchain.info RPC to detect deposits using Node.JS as server, using listTransactions method. Because blockchain.info doesn't has walletnotify api. When processing deposits, there is no ...
1
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4answers
890 views

If bitcoin fails as a currency, how will blockchain tech still be secure for other applications?

We often hear proponents, like Andreas Antonopoulos, say things along the lines of Bitcoin being an application of the Blockchain technology and that Bitcoin as a currency can fail, but blockchain ...
0
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0answers
18 views

What do people mean by solving bitcoin transactions? [duplicate]

I have been looking at a lot of posts about how bitcoins are generated. They keep talking about how miners do computations of other "transactions". Do they mean bitcoin transactions or other forms of ...
2
votes
2answers
202 views

How to generate a Litecoin Private key and correspondent Public Address in C#

I found this C# tool to generate addresses for Bitcoin (compressed and uncompressed): https://en.bitcoin.it/wiki/Bitcoin_Address_Utility https://github.com/casascius/Bitcoin-Address-Utility It ...
0
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1answer
77 views

How is UTXO tracked?

What is the best way to compute UTXO of any address? Do I have to traverse whole block chain each time? Is there a efficient way to compute it?
2
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1answer
111 views

Verifying Bitcoin ownership

Suppose Alice has 30 bitcoins from David. Now Alice wants to transfer amount 20 bitcoins to Bob. Now, Alice creates a transaction with Bob's bitcoin address. To prove authenticity and integrity, ...
15
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1answer
2k views

How is the whitepaper decoded from the blockchain (Tx with ~1000x m of n multisig outputs)

The whitepaper is apparently encoded at 54e48e5f5c656b26c3bca14a8c95aa583d07ebe84dde3b7dd4a78f4e4186e713, which is an m of n multisig Tx with 947 outputs (just under the scriptsig limit of 20kB!). ...
3
votes
3answers
776 views

How do I compose a transaction with OP_RETURN in Python?

Currently trying to figure out how to use Python to construct a transaction with OP_RETURN. I tried to encode the message myself, and had no luck. I found a function, OPReturn(), on the internet, but ...
3
votes
2answers
196 views

Non standard Tx with obscure OP codes: examples

I've been writing Python code to fetch various transactions and came across this: 77822fd6663c665104119cb7635352756dfc50da76a92d417ec1a12c518fad69. The script field is as follows: scriptPubKey: ...
0
votes
1answer
88 views

blockchain webgame - use api or actual blockchain to build database?

I am currently designing a blockchain based web game, and part of the game is to display data from the blockchain in table format on the site. The data will be updated peroidically, or in short ...
1
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1answer
425 views

Blockchain MySql Implementation - Updating Database

I know there are similar posts here about utilizing MySQL as the basis for an application which contains the contents of the blockchain, but i have not seen any on-point answers to the issue of ...
7
votes
1answer
212 views

How does merged mining work on a technical level?

In bitcoin, miners hash the header twice with the SHA256 function. This header consists of the fields listed below, as described by this question. version previousHashBlock merkleRoot time ...
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7 views

Book question on Bitcoin [duplicate]

I was wondering if you have any books in order to understand more in depth both Blockchain technology and Mining
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1answer
213 views

How to find Z value of multisig transaction?

for example this transaction: http://2coin.org/txinfo.aspx?txid=6c3dc603da32bba3f56f2b33053aaf0f0f17322386c0c6846786bffe49f6ef22&cur=BTC Script not of right size to be a scriptSig, expecting 2 ...
3
votes
1answer
148 views

Is there a fixed order for all transactions in the block chain?

Every block in the block chain contains a list of transactions. This list has a certain order which is basically set by the miner introducing the block. The merkle root in the block header requires ...