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.