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).
Which git meets.
How does it “certainly meet it”? There is no consensus mechanism in git, new blocks are not replicated across the network, there is no network at all, git works offline. You can replicate changes with remotes but there is no “git network” in any similar sense. And conflicts are definitely not resolved automatically. And the git hashes are certainly not cryptographic.
That’s 4 ways it doesn’t meet the definition. You could maybe stretch the meaning of a network to make it 3.
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.
A hash function doesn’t check if a signature is valid. Neither does git. Blockchain does check.
