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'!

259 questions with no upvoted or accepted answers
Filter by
Sorted by
Tagged with
5
votes
1answer
431 views

Can*t call chainActive.Tip()->nHeight in core.cpp

I want to call chainActive.Tip()->nHeight in core.cpp. It is not possible, I am interested in every idea. https://github.com/LIMXTEC/BitSend/blob/DEV-joshafest/src/core.cpp Here is an example : ...
4
votes
1answer
70 views

What is the difference between Consensus and Distributed Consensus?

This is more of a clarification than as a question. Since I didn't have the rep to post a comment in this question, I'm putting this itself as a question. Sources I've referred till now: A ...
3
votes
4answers
3k views

Are there any opensource PHP cryptocurrency exchange/marketplace

As the title suggest, are there any opensource PHP cryptocurrency exchange/marketplace. Most of the ones I found does not seem to work or are abandoned.
3
votes
0answers
576 views

Verification progress decreasing when validating genesis block

I've been experimenting with the litecoin source and have decided to make my own token network for personal use. I've mined my own genesis block, and assigned unique identifiers for base58Prefix and ...
3
votes
0answers
489 views

blockchain - Anti-virus service

I hope this is the right place to ask a question on how does block-chain help this theoretical requirement. I have also asked this question on SO; so far, no response. And, Ethereum SE is still in ...
3
votes
0answers
807 views

Querying insight-api to dump all addresses with a positive balance

It's been some time I've been using 'insight-api' (https://github.com/bitpay/insight-api) and I couldn't find any documentation / anything helpful to query leveldb in a way that all addresses with a ...
3
votes
1answer
167 views

What is the best way to implement withdrawal in online service?

Suppose we have a service, which holds user balance in Bitcoin. How to implement withdrawal from bitcoin perspective? Which RPC call to use? How to archive transaction to have a proof of sending ...
2
votes
0answers
92 views

Proof-of-Stake: How to ensure immutability of the blockchain?

In Proof-of-Work, a miner tries to solve PoW puzzle based on the hash of previous block, such that in case of changing block B_i, all blocks after that (blocks B_i+1, B_i+2, ...) are no longer valid ...
2
votes
1answer
69 views

How do different implementations of the Bitcoin Cash client know which type of coin they're processing?

TL;DR: Where in this code does the SV client figure out that it's not processing an ABC blockchain? This image prompted my question. There are a couple different mutually incompatible (I am assuming ...
2
votes
1answer
137 views

Different balances in API block explorers for BTC

BTC.com block explorer shows bigger balance than for example Insight or Blockchair. For example: https://btc.com/1FLDCfr9iG7n6bAdGsqBXmhaLgC4aSze72 https://insight.bitpay.com/address/...
2
votes
2answers
189 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.
2
votes
0answers
201 views

Is my understanding of Blockhain Endianness correct?

I know questions on this topic have been asked to death in a number of different ways. I also know that what endian order refers to specifically is dependent on context. What I want are some ...
2
votes
0answers
157 views

Blockchain explorer for regtest mode

I'm looking for a Bitcoin blockchain explorer that will work in "regtest mode", mostly for demo proposes. Any suggestions?
2
votes
0answers
369 views

How to delete last n blocks / roll back to specific block number in Bitcoin Core? (Like `monero-blockchain-import --pop-blocks n`)

I have Bitcoin Core's bitcoind running and synced in a VM. Now I want to clone the VM and run one of the various hard forks (such as Bitcoin Cash) in the clone. The plan is to roll back my copy of the ...
2
votes
0answers
77 views

Question about BIP70 and bitpays recent card top up changes

Okay so bitpay just sent out an email that outlines some changes to their card top-up process. Apparently, they are implementing BIP70 and I am honestly not very familiar with what exactly that is. I ...
2
votes
1answer
347 views

Understanding a Wallet Restore

This is my first post on block chain related programming so please excuse my ignorance. I find the terminology in the BIP32 and BIP39 specs hard to understand so I'm trying to confirm my understanding ...
2
votes
0answers
1k views

Is there any blockchain-based mail services available?

According to technology behind the Bitcoin, I'd be interested in using decentralized blockchain-email. Cryptamail was only one I found but they've been told that it is in beta right now but last ...
2
votes
0answers
92 views

The blockchain lookup speed in a local machine

How to determine the exact required time (seconds, milliseconds) to find a particular block when searching within a local blockchain using address? Is there any way to make a benchmark to study the ...
2
votes
0answers
257 views

bitcoind verifychain vs reindex

actually this is not Bitcoin but Litecoin 0.13.2 on Linux Mint, litecoind stopped with "bus error" just on start verifying blocks: tail ~/.litecoin/debug.log ... 2017-05-06 21:15:26 Verifying last ...
2
votes
0answers
134 views

Method to measure “distance” between 2 transaction id's

Is there a blockchain tool/code that takes two BTC transaction ID's and determines a distance between them. It's 2017 and Bitcoin Privacy (aka trying to walk around in the public without a sign over ...
2
votes
0answers
222 views

Can't access Blockchain.info API using ASP.NET

I am using ASP.NET(VB) to call API Try Dim strUrl As String = "https://blockchain.info/tobtc?currency=USD&value=500" Dim request As WebRequest = HttpWebRequest.Create(...
2
votes
0answers
240 views

Is there a robust way to test for a corrupted blockchain?

While running bitcoind I once had the blockchain get corrupted and it manifested as a non-obvious error message which unfortunately I can't remember. I would like to know if there is a robust way to ...
2
votes
0answers
246 views

How do i loop through all the related address in a given wallet address

I am using bitcoin block chain API, it is possible to get amount sent in a transaction id and the addresses it was sent to. My problem is getting the RELATED ADDRESSES to the address that sent the ...
2
votes
0answers
374 views

Synchronisation stopped at one specific blockchain

I've successfully been using Bitcoin core for the past months, but since two weeks ago its synchronisation is always stopped at the exact same blockchain. 2 weeks later, sync is behind by 2 weeks. And ...
2
votes
1answer
1k 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 ...
2
votes
0answers
107 views

Can we know the address list which blockchain API has created?

I am currently using blockchain payment API. This API has created the addresses for receiving payment. https://blockchain.info/api/api_receive Can we know the list of unused addresses this ...
2
votes
0answers
148 views

Iterating through LevelDB or .DAT files to enumerate bitcoin addresses

I'm looking for a library that can parse either the .DAT files or the .ldb files to enumerate bitcoin addresses. Alternatively, if that can't be done via the standard .dat or .ldb, I'll take a ...
2
votes
0answers
387 views

How will Bitcoin and the Blockchain scale in the future?

I wonder how the whole Bitcoin blockchain system will scale in the future. Given the fact that the size of the blockchain will grow exponentially (roughly a tenfold every ~3 years, looking at the ...
2
votes
0answers
103 views

Bitcoin .11 Initial Blockchain Download Problem with OS X 10.10

I am loading the blockchain for a new wallet. Initially I had problems due to ISP issues. This issue is fixed and I now have 8 outbound connections working well with ping times ranging from 50-800 ms. ...
2
votes
0answers
202 views

Get as many blocks as possible (stale, invalid, orphans)

I would like to download (and access) as much blocks as possible - including stale (extinct) blocks, orphans blocks and invalid blocks. I have 0.11 official client. My node is already synchronized but ...
2
votes
0answers
137 views

What restrictions does merged mining place on the sidechain?

What restrictions are imposed by merged mining on the structure or functionality of a side chain (besides it having to use the same PoW schema)? For example, could the side chain have a higher block ...
2
votes
0answers
184 views

Filter transactions per block 50 BTC or Higher

I'm using the blocktrail python api, to try and display transactions above 50 BTC per block for a visualization project. I think I'm almost there but can anyone help me understand where I'm stuck? ...
2
votes
0answers
778 views

Just installed bitcoin, but it won't connect

Total newbie at bitcoin; long time Linux user. kubuntu precise 64: My first attempt was just to download it (a slightly older version than the one from the ppa below), untar it and run the executable....
2
votes
0answers
249 views

Bitcoin-qt database for BitcoinJ downloadBlockChain()

I am using bitcoinJ to develop a bitcoin based payment module for my project. I have the complete block chain downloaded/in sync with the network on the bitcoin-qt client. Is there a way I can use ...
2
votes
0answers
88 views

How can I record block solve times on OSX?

I need to be able to record the times blocks are solved as they are solved. Bitcoin-abe would be nice (overkill, actually) but I can't get it working on my mac. Anyone know of a mac compatible method ...
2
votes
0answers
665 views

How to use downloaded blockchain on ubuntu?

I am using a fresh install of Bitcoin and have no wallet with coins at this time, and want to use the Bitcoind service in short time (loading blockchain using bitcoind will take days because of slow ...
2
votes
1answer
703 views

What is the required input for python-bitcoinlib getrawtransaction command?

I am running a bitcoin node on my machine, fully synced with RPC commands enabled, rpc server live and txindex=1. In the command-line I can run the following RPC call and obtain the information ...
2
votes
1answer
711 views

Analysis on the Block Chain for Dead Bitcoins

My understanding is that the blockchain is currently 6.5 GB in size and will continue growing at a fairly hefty rate. Has anyone attempted to analyze the blockchain to attempt to determine dead ...
1
vote
0answers
31 views

Bitcoin stuck in old tablet with really old wallet - Can't send out or back up

I found an old tablet I have and it had some BTC on it. I got it in 2014 and it has a wallet called 'blockchain' on it which I think is blockchain.info at the time and now blockchain.com I am trying ...
1
vote
0answers
34 views

Blockchain.com wallet

Just a basic/general question, recently when I send bitcoin using blockchain.com's wallet I noticed within my transaction logs Received BTC to: BTC Trading Wallet. From: BTC Wallet directly after Sent ...
1
vote
1answer
65 views

How to improve bitcoin-qt when downloading blockchain? (very technical, dev views appreciated)

GitHub suggested discussing here before bothering developers with an issue. So be it! :) I'm running Bitcoin Core Version v0.20.1 and Linux Mint 18.3 on crappy old hardware. Pruning blockchain to 2 G ...
1
vote
0answers
34 views

Initial blockchain sync stuck on block 237158

Stuck on block 237158. Rebooting doesn't work. Do I need to start from scratch? admin@raspberry2bit:~ $ sudo tail -f /mnt/ext/bitcoin/debug.log 2020-10-26T08:48:30Z Loading addresses from DNS seed ...
1
vote
0answers
26 views

What are the potential causes for the “block not found on disk” error?

We run several bitcoin core nodes and load balance requests across them all. We occasionally hit the error "Block not found on disk" shortly after a new block gets confirmed, when looking up ...
1
vote
0answers
12 views

Why do we need 2F prepare certificates instead of just F+1 in PBFT?

I started reading PBFT and I could not understand: why do we need 2F prepare certificates? The client needs only F + 1 replies, not 2F, so why can't the same rule be applicable in the prepare phase of ...
1
vote
2answers
84 views

Trying to locate my bitcoins

I was working with a broker, now my "bitcoins" are in "blockchain", and I have no trace. How do I find them? How do I find said blockchain and bitcoins ?
1
vote
2answers
721 views

How to find Reused R values

I use software from https://github.com/ca333/rng-scanner , I try to find r that is reused. from the software I found results Bitcoin Address : 1GQdrgqAbkeEPUef1UpiTc4X1mUHMcyuGW In Input NR : 141 ~ ...
1
vote
0answers
67 views

Bitcoin Core wallet fails to load and requires reindex after I already did it

My Bitcoin Core is synchronized. But I can't open a wallet, it says that I might need a reindex. Though I already did it. Also I can't do dumpprivkey because it says that no wallet is loaded. How can ...
1
vote
0answers
31 views

Fork rate range in terms of network security

I am really new to bitcoin and am trying to understand the basics. Fork rate/Orphan rate is a measure of network security. The higher the fork rate, the more compromised the system. Also fork rate ...
1
vote
1answer
53 views

Problem with using blockchain for E-Shopping

I have a confusion with blockchain concepts. Blockchain is immutable. So we can have problems in using blockchain for shopping websites. Because if we use it for retail, people have a habit to return ...
1
vote
1answer
141 views

can we make a blockchain that works like torrent?

Is it possible to make a blockchain system that allows you to download specific blocks from the blockchain instead of the whole blockchain? In my case for example, I only need 1 giga of the whole ...

1
2 3 4 5 6