44
votes
Accepted
How does Bitcoin Cash implement replay protection?
Bitcoin Cash (aka Bitcoin ABC aka UAHF) provides two methods of replay protection, both of which are opt in. If you do not create transactions which use these features, then your transactions are ...
32
votes
What is a soft fork? What is a hard fork? What are their differences?
Softforks are forwards-compatible
Old nodes will accept blocks created by new nodes.
With a softfork, only miners will have to upgrade, or else they will end up on the losing fork. Users and ...
16
votes
What happens if two miners mine the next block at the same time?
What Nicolai said is not completely right.
The network would decide which one is the main chain according to the following block mined. Let's assume that block A and B are mined at almost the same ...
15
votes
When bitcoin forks, how do they decide which fork gets the original name?
One might think that the network maintaining the same consensus rules would be considered the original, and the project introducing a consensus rule change and thus creating a new network would be ...
12
votes
Accepted
What is transaction replay and replay protection?
What is a transaction replay
In the context of forks, transaction replay is when a transaction is valid on both sides of the fork. So a transaction can be played (i.e. broadcast) on both chains after ...
10
votes
What happens to coins after Bitcoin Cash fork?
If you have 1 Bitcoin (BTC) before the hard fork, you will have 1 Bitcoin (BTC) and 1 Bitcoin Cash (BCC) after the hard fork.
Whether you can spend those BCC depends on who has control of your ...
10
votes
Accepted
Preparing for Bitcoin Gold
Yes Coinbase has not mentioned supporting Bitcoin Gold or Not so to be safe definitely move your BTC to a wallet so you have control of your private keys.
On Oct 25th the fork will happen and on ...
9
votes
How can forks coexist even though only one of the is the longest chain?
For one, Litecoin is not a fork of Bitcoin. It relies on the same base code, but it is a separate network, and they do not share the genesis block.
Bitcoin Cash is a true fork of Bitcoin, in the ...
8
votes
Accepted
Is there actual consensus on the blockchain's tip or only until the next block?
No, there is no consensus until the next block is found. The network is experiencing a blockchain-fork. It will only mend once one of the tips pulls ahead by adding another block. Then all nodes will ...
8
votes
Accepted
Does my bitcoin multiply with every fork?
Note that the word "fork" can have several meanings. The more common one is a protocol change (either a soft or hard fork) where everyone switches to the new protocol. In this case there will still be ...
8
votes
Accepted
Why does everyone say that soft forks restrict the existing ruleset?
If this is true, then how are legacy transactions still present in the blockchain? Clearly, there are still plenty of transactions with non-segwit and non-taproot script types.
I'll focus on Taproot ...
7
votes
Accepted
What is the probability of forking in blockchain?
Actually, it is not related to the difficulty at all, rather just related to the expected time until the next block is found.
Block finding is a Poisson process.
The probability of x blocks occuring ...
7
votes
Accepted
Does bitcoin have the potential to be subject to a hard fork where miners are forced to choose which fork they will accept, like Etherum?
Yes, Bitcoin could also be subjected to a hardfork. In fact, there are members of the Bitcoin community that feel so strongly that the blocksize should be increased that they are proposing to do just ...
7
votes
Accepted
At what point does a hard fork occur?
A hard fork is something that happens when some of the nodes on the network follow a new set of rules that are in some way incompatible with the existing set of rules. It occurs upon mining the first ...
7
votes
Accepted
Can I claim my BCH if my BTC is held with Coinbase?
If you didn't move out your BTC before the fork, then your BitCoin Cash tokens remain with CoinBase. They are not really lost, but they might remain in their system for a while. Here is the ...
7
votes
Accepted
How does Bitcoin Gold implement replay protection?
I don't believe any replay protection has yet been implemented, they still have an issue open for it on the BitcoinGold repository here:
https://github.com/BTCGPU/BTCGPU/issues/51
I haven't dug into ...
7
votes
Is there a list of Bitcoin Forks?
There is this list on Wikipedia: https://en.wikipedia.org/wiki/List_of_Bitcoin_forks
Bitcoin Cash (Forked at Block 4785591, 1 August 2017)
Bitcoin Gold (Forked at Block 491407[2], 24 October 2017)
...
7
votes
Accepted
Does a 2009 node sync the whole bitcoin blockchain
In theory it can as the explicit consensus rules have not changed. However in practice, it will not be able to sync without some special modifications.
First of all, the network version is so old ...
7
votes
Accepted
Is every BIP actually a small fork?
Not every BIP is a fork (change in consensus rules). Some are standards for wallet software (like BIP32 and BIP39), the peer-to-peer protocol (BIP152) and other areas. The BIP repository classifies a ...
6
votes
Accepted
Can a hard fork effectively double the value held in bitcoin?
I'm not an economist, but…
No, that's very unlikely.
Starting from your assumption that the network splits into two persisting blockchains*:
The number of active participants of each network is ...
6
votes
Accepted
Segregated witness soft fork: how is the funding Tx made "ANYONECANSPEND"
It's not prepending a script with OP_0. It's a data push that contains the witness program hash, prepended by OP_0.
Old nodes will evaluate this as a script that just pushes two data items onto the ...
6
votes
Which blocks get to be checkpoints?
At least in Bitcoin Core, none. Checkpoints are legacy and will likely be removed at some point.
Checkpoints were originally introduced as a way to enable skipping of signatures in the historical ...
6
votes
Can the blockchain be outpaced by a chain of low-difficulty blocks?
Nate gave a good answer on the modern meaning of "longest chain"-- as a historical curiosity, the originally released Bitcoin software behaved like you were expecting and that attack would actually ...
6
votes
Accepted
How to detect a fork with bitcoin-cli?
You can use the getchaintips RPC, which will list all tips of the known block tree, including branches that were never active.
You may see for example:
{
"height": 420561,
"hash": "...
6
votes
What is the best way to prevent replay attacks in the event of a bitcoin hard fork?
One solution we brainstormed, was using some coins that were only valid on one chain (for example newly mined coins) and adding 1 satoshi of "taint" to all generated transactions. This would work but ...
6
votes
Accepted
Why not decrease the difficulty to increase capacity?
One problem is that lower block times mean an increased chance of forking, which makes head of the chain, and the system, less reliable.
Another problem is that it normally takes a block a few ...
6
votes
Accepted
How to claim Bitcoin Cash & Bitcoin Gold from paper wallet
Go to Blockchain.info
Sign up and after logging in, go to settings. Then in settings, you will see addresses as shown below:
Then click on Import Bitcoin Address as shown:
Then add your private key ...
6
votes
How bitcoin nodes update UTXO set when their latests blocks are replaced?
Bitcoin Core since v0.8 maintains "undo files" that contain the information necessary to undo the effect of a block on the UTXO set.
In a way you can see blocks as authenticated patches to be applied ...
6
votes
Accepted
How often does temporary fork occur and how long does it last?
Blockchain forks occur when two blocks are found at the same height. Only one of the two chaintips can become part of the best chain. Each full node will consider the first block it saw to be the best ...
6
votes
Accepted
What is a stale blockchain tip? Is it a blockchain tip missing the latest mined block?
(I don't think of this as a standard term, so the context was useful for me to figure out what this question was asking -- then I realized you're asking about a specific usage I have used regarding ...
Only top scored, non community-wiki answers of a minimum length are eligible
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