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 ...
Ava Chow's user avatar
  • 70.5k
17 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 ...
Murch's user avatar
  • 75.4k
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 ...
Ethan's user avatar
  • 161
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 ...
Ava Chow's user avatar
  • 70.5k
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 ...
smizzlov's user avatar
  • 350
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 ...
GottaMinute's user avatar
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 ...
Raghav Sood's user avatar
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 ...
Murch's user avatar
  • 75.4k
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 ...
Meni Rosenfeld's user avatar
8 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 ...
Ava Chow's user avatar
  • 70.5k
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 ...
Pieter Wuille's user avatar
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 ...
Murch's user avatar
  • 75.4k
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 ...
Jestin's user avatar
  • 8,812
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 ...
Rob's user avatar
  • 86
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 ...
meshcollider's user avatar
  • 11.8k
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) ...
Jean-François Beauchamp's user avatar
7 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 ...
Pieter Wuille's user avatar
7 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 ...
Murch's user avatar
  • 75.4k
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 ...
Vojtěch Strnad's user avatar
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": "...
Pieter Wuille's user avatar
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 ...
Pieter Wuille's user avatar
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 ...
G. Maxwell's user avatar
  • 7,727
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 ...
David A. Harding's user avatar
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 ...
Steve Ellis's user avatar
  • 1,072
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 ...
remedcu's user avatar
  • 1,093
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 ...
sdaftuar's user avatar
  • 599
6 votes
Accepted

How is network conflict avoided between chains?

The protocol messages on Bitcoin include a magic number to identify the network they belong to. Bitcoin's magic values are described for example on the Protocol Documentation page in the Bitcoin wiki: ...
Murch's user avatar
  • 75.4k
6 votes
Accepted

Does local blockchain database (blkXXXXX.dat) contain abandoned forks forever?

When my node realizes that the given block needs to be abandoned - does it leave it in the database or replace the block with a valid one? It remains on disk along with its entry in the block index ...
Ava Chow's user avatar
  • 70.5k
6 votes

Why is not good having forks in a blockchain?

if I imagine to work with isolated transactions chained each other according to money flow, then i understand that we wish to have a single chain because forks would mean the presence of double-spend ...
Ava Chow's user avatar
  • 70.5k
6 votes
Accepted

Theoretical attack on the network by companies

If the vast majority of the network including users, economic majority, miners, and some subset of the developers were to hardfork a blocksize increase, this would result in effectively two networks. ...
Murch's user avatar
  • 75.4k

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