Questions tagged [bitcoin-core]

This tag should be used for questions pertaining to Bitcoin Core. Bitcoin Core is an MIT-licensed Qt 5 GUI application for the original Bitcoin codebase. Additional/previous names include "Bitcoin-Qt", "Satoshi-Client", and "Standard Client". This tag should be used when referring to the Bitcoin Core software.

Filter by
Sorted by
Tagged with
7
votes
1answer
601 views

What are the trust assumptions in --assumed-valid in bitcoin core 0.14?

Please help me understand and distinguish the trust assumptions in the following three cases shown below. Specifically, please elaborate the attacks possible (even though completely theoretical) and ...
6
votes
2answers
3k views

Why does the initial blockchain download get stuck part way through?

I am trying to get Bitcoin up and running on a fairly underpowered laptop and Windows Vista using Bitcoin-Qt 0.5.0.1. After installing and starting the program, I am stuck at at the syncing stage at ...
4
votes
2answers
600 views

Does the satoshi client always send the change of a transaction to a newely generated address?

Experimentally, this seems to be the case, but is it always like this or depends on some details? Also, does it generate a new address each time this is done, or first searches the wallet if there is ...
4
votes
3answers
2k views

Can I sell my BTC and still claim my BCH?

I held a small amount of BTC back in August (had them since 2014) but now wish to sell them. Do I need to claim my BCH before selling my BTC or am I correct in thinking that the two completely ...
3
votes
2answers
3k views

Since which version is the mining functionality removed from the wallet?

As I'm starting to learn to create a new altcoin, I found there is a remarkable difference between old and new Bitcoin/Litecoin Core wallet: old versions (0.6.9 of Litecoin) have mining functionality ...
3
votes
1answer
799 views

Unusual Version Number in Blocks

I've noticed recently that some blocks contain version numbers that are not the traditional 0x10000000 or 0x20000000. For example, this block, has a version number of 0x3FFFE000 instead of 0x20000000 ...
28
votes
2answers
11k views

When should I use -reindex-chainstate and when -reindex

What is the difference between the options -reindex and -reindex-chainstate? Is one of the options faster? When should each option be used?
17
votes
2answers
13k views

ECDSA r, s encoding as a signature

An ECDSA algorithm when signing a given messages produces a pair of outputs, r and s. How, given a sigStr from a Tx can one extract r and s? Are they just concatenated byte arrays of a specific length,...
21
votes
1answer
15k views

What is P2PK, P2PKH, P2SH, P2WPKH - ELI5

Explain like I'm 5 years old and my other half of the brain is surgically removed :) I don't want to put a lot of stress on my brain Also what is the difference between BTC held in P2SH and Unspent ...
19
votes
6answers
5k views

Merkle Root and Merkle Proofs

This is one of those questions that everyone seems to write about but the same bad explanations are just plagiarized from site to site. Edit: The heart of my question is why Merkle trees are claimed ...
24
votes
2answers
12k views

Bitcoin-Qt command line control on Mac

I'm trying to communicate with the new Bitcoin-Qt -server via a command line on Mac. I run ./Bitcoin-Qt -server, the application starts, but my terminal window is stuck on an empty line (no matter ...
18
votes
5answers
20k views

How to decode private key from Android Bitcoin Wallet?

I want to import my private key from the android's Bitcoin Wallet (the one created by Andreas Schildbach) but it can export it only in an encrypted way. How do I decrypt the file so I can import the ...
15
votes
1answer
11k views

How to generate SegWit address

How do I generate a SegWit address using Bitcoin Core CLI? Also will I be able to redeem those outputs and send them to a "legacy" address? If so, will this second transaction be accepted by older, ...
13
votes
1answer
1k views

Where in Bitcoin Core does it do X?

Note that this is a general question and answer designed to serve as a guide for finding things in Bitcoin Core. Where in Bitcoin Core's source code does it do X? How can I find that code by myself? ...
13
votes
1answer
9k views

How to get a bitcoin address's balance?

I know blockchain.info has an API: https://blockchain.info/q/addressbalance/134dV6U7gQ6wCFbfHUz2CMh6Dth72oGpgH gets the bitcoin address's balance,but it's not open source and must connect to the ...
11
votes
4answers
6k views

Is there a way to not pay the transaction fees when using the standard Bitcoin client?

I tried sending one satoshi (0.00000001 BTC) to one of my friend and the client always showed a dialog prompting me to pay 0.0005 BTC in fee, with the only options being OK (pay the fee) or cancel (...
9
votes
2answers
6k views

Is there a light (SPV) version of bitcoin core (bitcoind)?

I'm trying to develop an SPV Bitcoin client which makes use of a library requiring bitcoin core (a running bitcoind service). However, from what I understand, Bitcoin Core is full node, meaning that ...
0
votes
1answer
3k views

Cannot mine Genesis / First Block (PIVX Fork / Clone)

Whatever I do, I am unable to mine the 1st block after the genesis block. All the while, I have assumed that I have mined the Genesis block, and I am unable to mine the 1st block using "setgenerate ...
12
votes
1answer
2k views

How many addresses does my wallet.dat contain? Do I need to make a new backup every time I make a transaction?

I'm having little problem here, trying to figure out the safest way to backup my wallet.dat to make sure that no BTC may be lost in case of recovery. I'm not sure how the process of adding new ...
5
votes
1answer
6k views

Transaction refund address

In the what’s new in Bitcoin Core 0.9.0 notes there is a reference to a refund address. I tried to look it up in the forums and the wikis but I came up with nothing. How can I set a refund address ...
4
votes
2answers
2k views

Why would Bitcoin-QT attempt to charge a processing fee, when I have my transaction fees set to zero? [duplicate]

I'm attempting a test transaction of an amount less than 0.0015 BTC with my transaction fee set to 0 BTC, yet I'm getting this message: The total exceeds your balance when the 0.0015 BTC ...
2
votes
1answer
611 views

How to save the bitcoin core (bitcoin-qt) database for later?

Say I've received some Bitcoin using the Bitcoin Core wallet on some linux machine. Say I'm done playing for now. So now I want to free some disk space by deleting the huge database from this machine ...
2
votes
2answers
526 views

Why does importmulti not support zpub and ypub?

As far as I can tell importmulti does not work with zpub/ypub. Why not? FWIW I prefer only to deal with xpubs, but I am curious.
19
votes
3answers
7k views

How can I limit bandwidth usage in Bitcoin-qt client?

I've just finished the intial blockchain download/verify in my BitcoinQt client (17 hours..) and I now see that BitcoinQt is happily eating all of my upstream bandwidth. (About 110kByte/sec on my ADSL ...
16
votes
3answers
485 views

What happens if the developers make a controversial change to the “standard” client?

One criticism I commonly hear of Bitcoin is that it merely transfers trust from some sort of central bank or government entity to the developers of the main project. Can anyone provide a clean ...
11
votes
1answer
903 views

What BIPs are supported by the standard client Bitcoin Core?

There is different BIP, each has a status. I read somewhere that BIPs are not considered part of the Bitcoin protocol until "active". Nevertheless, Bitcoin Core seems to support a number of BIPs that ...
10
votes
2answers
758 views

How do I spend bitcoins from multiple wallets in a single transaction?

Using, e.g., the Bitcoin Core command line, how could I spend bitcoins from multiple wallets in a single transaction? This comment says: instead of sending the transaction to the network, you send ...
9
votes
2answers
7k views

What does Bitcoin Core's “Coin Control Features” do and how do I use it?

What is Bitcoin Core's "Coin Control Features"? How do I use it, and what can I do with it?
8
votes
2answers
15k views

Can you mine bitcoins with an intermittent Internet connection?

I've got a very precise question and this is not a dupe of: Does Bitcoin rely on the internet? My question boils down to: when you mine bitcoins, how "often" does the computer/hardware doing the ...
8
votes
2answers
926 views

How does the standard client prioritize transactions?

I've heard that the standard client prioritizes which transaction to relay based on the Bitcoin Days Destroyed and the fee paid on the transaction, but what is the exact formula used to determine ...
8
votes
2answers
8k views

Backing up my bitcoin wallet - is wallet.dat all I care about?

I know that there are many duplicates of this but I'm hoping that the way in which I word this explains and helps not just me, but others as well. In any of the coin wallet bitcoin and the alt coins,...
7
votes
2answers
5k views

What are seednodes?

A follow up from a comment on this answer. What are seednodes, and how do they differ from fallback nodes?
7
votes
1answer
970 views

Expected use model for PSBT

I want to use Bitcoin Core to create a PSBT for offline signing (cold storage) of a multisig p2wsh-in-p2sh address, such as that created by Glacier. Based on the PSBT doc I assume I want the online ...
6
votes
2answers
2k views

Import multiple watch-only addresses using importaddress?

With the importaddress RPC command it is possible to import one watch-only address. But how can I do that with, let's say, 100?
6
votes
2answers
3k views

How do you sweep a paper wallet with Bitcoin-Qt?

Sweeping involves importing a private key, then sending it's entire balance to a new address in your wallet via a new transaction. This would protect your paper wallet's bitcoins from being stolen if ...
6
votes
1answer
1k views

How secure are the DNS servers for Bitcoin?

With the version 0.6, Bitcoin introduced the DNS servers that populate the initial peers for new clients. How secure are those servers in terms of being immune to takedown attacks, or injection of ...
5
votes
1answer
992 views

How to get BIP34Hash and nMinimumChainWork?

I'm interested in the technical question of how you got BIP34Hash and nMinimumChainWork. The changes were introduced here: nMinimumChainWork: https://github.com/bitcoin/bitcoin/commit/...
4
votes
3answers
6k views

get Armory to use an existing blockchain?

I'm trying to set up Armory but it wants to download the whole blockchain. The thing is I already have the blockchain downloaded on the same machine for bitcoin-qt. Is there any way to get Armory to ...
4
votes
2answers
5k views

How to move the blockchain data while still being able to use the wallet?

Using the standard client, Bitcoin-Qt, v0.8.1: (win10x64) I would like to move the blockchain data from its default location to a different location (maybe even an external disk or NAS drive). What ...
4
votes
3answers
8k views

Can I remove the passphrase from my Bitcoin Wallet?

I'm using the standard Mac Bitcoin client and I added a passphrase. I'd like to remove that passphrase. Is that possible?
2
votes
1answer
739 views

interacting with bitcoin over docker

I've created a docker container of an ubuntu machine, loaded it up with all the dependencies specified in the unix build doc and then built bitcoin and run it with the following command: ./src/...
2
votes
1answer
2k views

Data directory issue

I have everything set up normally. My only issue is that my data directory is in C:\Users\User Name\AppData\Roaming\Bitcoin. Normaly this is what you would want, but, if you noticed, my username has ...
2
votes
2answers
2k views

How to get balance by any address using rpc bitcoind?

How to get balance of any address using rpc bitcoind? I mean getting by address the list of his unspent outputs in view something like this: TxHash;Value;Noutput.
2
votes
2answers
2k views

How does the Bitcoin Standard Client wallet encryption work?

I encrypted my wallet using Bitcoin QT, then closed the application. When I restarted Bitcoin QT, it did not ask for the passphrase. But I could still access the wallet. How is it possible to access ...
1
vote
1answer
754 views

testnet3 node sync process is very slow

My config file is similar to this: testnet=1 blocksonly=1 rpcport=5000 server=1 listen=0 prune=1000 dbcache=16000 rpcallowip=0.0.0.0/0 rpcuser=someuser rpcpassword=somepass I have started the ...
0
votes
1answer
169 views

Bitcoin ABC, When Fed Bitcoin Core Chain Syncs to Aug 1 6:23AM 2017, Then Freezes

I've installed Bitcoin ABC, set bitcoin.conf to point at a copy of my directory from Bitcoin Core, and let it sync with the network. All was well until it froze at the fork (Aug 1, 2017, 6:23AM). ...
-1
votes
2answers
359 views

Free bitcoins are real? [closed]

That's confusing the bitcoins used for marketing are real or not.. like some posted a code in facebook or in social media for free bitcoin so those bitcoin are real or a just marketing, hacking ...
15
votes
3answers
7k views

Attacking Bitcoin with a supercomputer

The difficulty in Bitcoin is recalculated every 14 days. What if immediately after this difficulty adjustment someone targets Bitcoin nodes with a supercomputer and start creating new blocks? Such ...
11
votes
3answers
2k views

Why are m-of-n transactions not used today?

BIP 11 supports m-of-n transactions. While BIP 16 and BIP 17 are being debated and voted upon, I have to ask: why haven't there been evidence of BIP 11 used in for m-of-n transactions? All that BIP ...
10
votes
1answer
3k views

Does the Bitcoin Qt client have a minimum transaction fee?

I'm trying to transfer all of my 0.1 BTC located in one wallet to another wallet. I don't care how long it takes to finish, so I'd rather send it without paying any transaction fee. I'm new to this, ...

1
2
3 4 5
7