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.
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.)
A hash function doesn’t check if a signature is valid. Neither does git. Blockchain does check.
