BCH Wallet Developer Says SegWit Changes Bitcoin’s (BTC) Definition
Jonald Fyookall Segregated Witness Changes The Definition of a Bitcoin
Back in 2017, Dr. Peter Rizun explained that Segregated Witness (SegWit) changes the definition of Bitcoin. The white paper says that Bitcoin is ‘an electronic coin as a chain of digital signatures.’
And indeed, according to Jonald Fyookball, breaking the chain of digital signatures is actually removing an integrity check in the Bitcoin ledger. When we talk about Bitcoin, one of the most important types of data are digital signatures that prove that a coin was properly transferred. Even if the network suffers a 51% attack, users’ funds are safe because of the signatures.
With digital signatures, Bitcoin is able to establish an important data integrity check that secures the transactions. And this is very important for users, because this security model ensures that for a coin to move, the corresponding signature has to be produced and it has to be included in a transactions and published on the blockchain.
Additionally, producing a fake signature is hard, and nobody can steal the funds of another user if they do not have the private keys. Once a theft occurs, it is possible to look at the signature registered on the blockchain and verify that this happened. But as Mr. Fyookball says, this is true for all non-Segwit transactions in Bitcoin.
SegWit Removes Integrity Checks
As Rizun explains, signatures are an integral part of the Chain. He explains about it:
“Carol can only verify the complete chain of ownership if all the signatures are all outside of the chain. If even none of the signatures exist, or maybe none of the signatures were even real to begin with, Carol can still validate the chain of custody.”
Then, Rizun uses the word custody instead of ‘the chain of ownership’ because SegWit shows custody.
In SegWit, there is a signature but it is not required to include it in the input of the transaction. But instead, it is excluded with the intention to eliminate malleability. The data is there, but the data integrity check is not there because it is not necessary to have the complete transaction the next time that the coin is spent.
Each block needs to have a hash value that represents the set of signatures for the SegWit transactions. Miners are those responsible to make sure that the signatures are correct before accepting a block. But using SegWit, signatures do not provide linkage from one transaction to the next.
The security model has changed. SegWit supporters say that the miners validate all the signatures, and in order to break that model it is necessary a 51% attack. The integrity check has been discarded and replaced with a total reliance on miners.
Fyookball compares that with wearing belt and suspenders:
“This is aking to wearing a belt and suspenders for years to make sure your pants never fall down, then one day takin off the belt and proclaiming ‘I’m still wearing suspenders,what could go wrong?’”
What Happens In SegWit If Coins Go Missing?
This is a key question that Fyookball asks. He says that in Bitcoin, the signature has to be on the chain, and it can be searched on any explorer. A user is able to point to empty witness data on an explorer as evidence. It is possible, though, that any disappearance of witness data will be a public anomaly.
If a miner fails to publish all the witness ata because of different problems, it might be possible for other miners in the network to accept the block without all he witness data getting published.
If one day there is a 51% attack, in the Bitcoin security model, there have never been any instances where an invalid signature was accepted. The anomaly would be provable. But the situation is different if the miners decide to keep building on a block without all the signatures.
Fyookball also asks what would happen if there is political pressure applied to mining pools to steal some of the funds without signature.
He also mentions that he is not pro-SegWit but he wants to be objective and ovestate the problem. At the moment, there haven’t been any problems with Segregated Witness as of today. The signatures are still there, but the integrity check might not be. And indeed, no database design is perfect.
Segregated Witness is a development that has been proposed by the Bitcoin Core development team. And Bitcoin Core supporters have been positively accepting these proposals. But Fyookball says that there are some contradictions in the roadmap.