Blockchain is a nebulous buzzword with a vague meaning. But I have yet to see a sensible definition of a blockchain that doesn’t include git. At the end of the day they are both just Merkle trees.
Please share a source! I can’t find anything as robust as a whitepaper (the bitcoin whitepaper doesn’t use the term).
NIST informally defines it as:
A distributed digital ledger of cryptographically-signed transactions that are grouped into blocks. Each block is cryptographically linked to the previous one (making it tamper evident) after validation and undergoing a consensus decision. As new blocks are added, older blocks become more difficult to modify (creating tamper resistance). New blocks are replicated across copies of the ledger within the network, and any conflicts are resolved automatically using established rules.
Which git certainly meets this.
IBM informally defines it as:
Blockchain is a shared, immutable ledger that facilitates the process of recording transactions and tracking assets in a business network. An asset can be tangible (a house, car, cash, land) or intangible (intellectual property, patents, copyrights, branding).
Oh a 3rd definition, that definitely hurts the case that blockchain is vague ill defined term. If it were a well-defined term, there would be whitepapers defining it like merkle trees or bitcoin. Blockchain is just a marketing term defined by businesses, not scientists or engineers and thus is vague and variable.
I also don’t think your definition is a very good definition. Do you think git fundamentally changes when it moves from sha1 to sha256? Or are you referring to the fact that the payloads of cryptocurrency’s blockchain is required to be signed (just like you can optionally require git commits to be signed)? I don’t think that’s fundamental to blockchain either.
Only cryptographicly valid changes are allowed to blockchain state. All data can be modified in git.
No. You can’t modify the chain in git. Each commit is an immutable snapshot of the repository. To change history you have to create a new hash and then broadcast that to everyone that they should stop using the old one. Depending in how your network is setup you may onky have to convince a centralized server, or you might have to convince 51% of the actors on your network or you may just choose to only form a network that agrees with you. You could alter bitcoin’s blockchain too, but you’d need 51% of the network to agree with you.
Oh a 3rd definition, that definitely hurts the case that blockchain is vague ill defined term.
The phrases used to describe the technology to the public may change, but the technolgical approach doesn’t
If it were a well-defined term, there would be whitepapers defining it like merkle trees or bitcoin.
There are hundreds of blockchain whitepapers, all of which link blocks of data via hash functions and only accept state changes if they are valid and cryptographicaly signed.
Blockchain is just a marketing term defined by businesses, not scientists or engineers and thus is vague and variable.
If we were discussing web3 or Metaverse then you may have a point. But no-one in tech is confused about what blockchain is anymore.
Do you think git fundamentally changes when it moves from sha1 to sha256?
No.
Or are you referring to the fact that the payloads of cryptocurrency’s blockchain is required to be signed
Yes. Exactly this.
(just like you can optionally require git commits to be signed)?
Optionally is the key word. Blockchain transactions must be signed, and they must be accepted as following the blockchain rules by validators.
I don’t think that’s fundamental to blockchain either.
Find me a blockchain that doesn’t require signed transactions to make state changes.
No. You can’t modify the chain in git.
I didn’t say anything about modify the chain.
Each commit is an immutable snapshot of the repository.
A commit can contain any data it likes. A commit to a blockchain is highly restricted. Only cryptographicly valid rule following changes are allowed to blockchain state.
Optionally is the key word. Blockchain transactions must be signed, and they must be accepted as following the blockchain rules by validators.
But this is just a policy decision, not a property of the technology. You can easily implement a script that checks if every commit from remotes are signed, accepts them if they are and drops them if they aren’t or the signature is invalid.
If you contribute to a project where the majority require signed commits, then you need to sign commits in order for your change to be integrated into the consensus.
That has nothing to do with the technology itself, just with the application.
So if you state that signatures are required to be a blockchain, then you can use git to create a blockchain, by just having that policy.
(IMO I wouldn’t say that signatures are required, just that blockchains usually have them.)
You can easily implement a script that checks if every commit from remotes are signed, accepts them if they are and drops them if they aren’t or the signature is invalid.
Now add some logic to check whether the actual data is valid (i.e. bob has enough coins in his account to send to Charlie).
Make some incentive to ensure only the main branch survives and forks are either eliminated or merged.
Automate
Now git replicates blockchain’s functionality.
So if you state that signatures are required to be a blockchain, then you can use git to create a blockchain, by just having that policy.
Yes, but add automatically processing the content of the commit for validity and incentives to reduce the number of forks.
(IMO I wouldn’t say that signatures are required, just that blockchains usually have them.)
Without public key cryptography you just have a hash linked list (like Git).
While blockchain is well defined, it in itself is not a product but a technology. I think what the other commenter is getting at is that simply saying something “is blockchain” means very little because what the blockchain does depends on the implementation, so when used in marketing it’s just a nebulous buzzword in that it doesn’t actually give you much information about what the product is. Same with terms like cloud, AI, virtual reality, etc.
The dude who owns the election server won’t be able to manipulate results in any way.
Sure he will. He can just ignore votes for one candidate and not add them to the chain. Blockchains are only resistant to manipulation if they’re distributed and people agree on the canonical version. Even then if enough people agree to manipulate them they can, like they did with Ethereum.
Blockchain is a nebulous buzzword with a vague meaning. But I have yet to see a sensible definition of a blockchain that doesn’t include git. At the end of the day they are both just Merkle trees.
Git is pretty useful imo.
Well yes but can you pump and dump git commits ?
Blockchain is pretty well defined.
Git doesn’t have update rules that are only valid if signed by a particular private key.
Please share a source! I can’t find anything as robust as a whitepaper (the bitcoin whitepaper doesn’t use the term).
NIST informally defines it as:
Which git certainly meets this.
IBM informally defines it as:
Which git meets.
Git is hash linked, not cryptographicly linked. Only cryptographicly valid changes are allowed to blockchain state. All data can be modified in git.
Yes. IBMs definition is bad and could equally apply to git. They’ve totally forgotten about the private key aspect.
I’ll see if I can source a better definition online, but make no promises.
Edit: https://aws.amazon.com/what-is/blockchain/ the last line is not applicable to Git
Oh a 3rd definition, that definitely hurts the case that blockchain is vague ill defined term. If it were a well-defined term, there would be whitepapers defining it like merkle trees or bitcoin. Blockchain is just a marketing term defined by businesses, not scientists or engineers and thus is vague and variable.
I also don’t think your definition is a very good definition. Do you think git fundamentally changes when it moves from sha1 to sha256? Or are you referring to the fact that the payloads of cryptocurrency’s blockchain is required to be signed (just like you can optionally require git commits to be signed)? I don’t think that’s fundamental to blockchain either.
No. You can’t modify the chain in git. Each commit is an immutable snapshot of the repository. To change history you have to create a new hash and then broadcast that to everyone that they should stop using the old one. Depending in how your network is setup you may onky have to convince a centralized server, or you might have to convince 51% of the actors on your network or you may just choose to only form a network that agrees with you. You could alter bitcoin’s blockchain too, but you’d need 51% of the network to agree with you.
The phrases used to describe the technology to the public may change, but the technolgical approach doesn’t
There are hundreds of blockchain whitepapers, all of which link blocks of data via hash functions and only accept state changes if they are valid and cryptographicaly signed.
If we were discussing web3 or Metaverse then you may have a point. But no-one in tech is confused about what blockchain is anymore.
No.
Yes. Exactly this.
Optionally is the key word. Blockchain transactions must be signed, and they must be accepted as following the blockchain rules by validators.
Find me a blockchain that doesn’t require signed transactions to make state changes.
I didn’t say anything about modify the chain.
A commit can contain any data it likes. A commit to a blockchain is highly restricted. Only cryptographicly valid rule following changes are allowed to blockchain state.
But this is just a policy decision, not a property of the technology. You can easily implement a script that checks if every commit from remotes are signed, accepts them if they are and drops them if they aren’t or the signature is invalid.
If you contribute to a project where the majority require signed commits, then you need to sign commits in order for your change to be integrated into the consensus.
That has nothing to do with the technology itself, just with the application.
So if you state that signatures are required to be a blockchain, then you can use git to create a blockchain, by just having that policy.
(IMO I wouldn’t say that signatures are required, just that blockchains usually have them.)
Now add some logic to check whether the actual data is valid (i.e. bob has enough coins in his account to send to Charlie).
Make some incentive to ensure only the main branch survives and forks are either eliminated or merged.
Automate
Now git replicates blockchain’s functionality.
Yes, but add automatically processing the content of the commit for validity and incentives to reduce the number of forks.
Without public key cryptography you just have a hash linked list (like Git).
While blockchain is well defined, it in itself is not a product but a technology. I think what the other commenter is getting at is that simply saying something “is blockchain” means very little because what the blockchain does depends on the implementation, so when used in marketing it’s just a nebulous buzzword in that it doesn’t actually give you much information about what the product is. Same with terms like cloud, AI, virtual reality, etc.
Yes. There were a lot of companies selling “blockchain base” solutions where blockchain wasn’t really needed in the solution at all.
Then it was Metaverse based solutions. (I would argue VR is well defined)
Now it’s AI solutions.
But I think “cloud” is now post that marketing phase, and blockchain is heading that way.
Who decides to commit changes though? A human. A human who can be corrupt.
The best use case for blockchains in my opinion is elections. The dude who owns the election server won’t be able to manipulate results in any way.
While manipulating results isn’t impossible in case of a blockchain, it is still very very difficult.
Sure he will. He can just ignore votes for one candidate and not add them to the chain. Blockchains are only resistant to manipulation if they’re distributed and people agree on the canonical version. Even then if enough people agree to manipulate them they can, like they did with Ethereum.