[sirclueless]

The common consensus for the term "blockchain" is not based on the 1991 paper, but on Bitcoin's use of similar technology to make a distributed ledger. The term itself is relatively recent, and was not used until well after Satoshi's paper. For example, Harvard Business Review describes it this way:

"At its most basic, blockchain is a vast, global distributed ledger or database running on millions of devices and open to anyone" [1]

That incorporates at least two concepts that are typically associated with the term "blockchain" that go beyond the basic cryptographic data structure: they are distributed, and they are open. Lots of technologies use a similar data structure; git uses a similar data structure. But when a silicon valley startup comes to you and pitches you on their "hot new blockchain tech" they probably don't mean git.

[1]: https://hbr.org/2016/05/the-impact-of-the-blockchain-goes-be...

[zaarn]

I have to agree with GP here.

>but on Bitcoin's use of similar technology to make a distributed ledger.

That doesn't really change a thing. Bitcoin merely uses a blockchain to ensure consensus, if all nodes are trusted then you don't need proof of work and you can switch to simply linking the list (see Git or Ethereum Testnets), and the contents of the blockchain are mostly irrelevant too (you can put anything on there, transactions are merely one type of thing you put in there)

At it's most basic, a blockchain is just a directed graph of nodes where a cryptographic method links two nodes together in a child-parent relationship. Everything else is just added fluff for the specific usecase.

[sirclueless]

I think a lot of people would disagree with you. There are obviously many methods besides proof-of-work to achieve consensus, but a blockchain cannot properly be called a "blockchain" unless there is some consensus protocol. Not every DAG of digital hashes is a blockchain.

Under your definition, every CBC mode stream cipher could be called a blockchain, which just makes the term meaningless. It was coined for a specific purpose: to describe how Bitcoin and related cryptocurrencies operate at a technical level, especially how they guarantee integrity and prevent double-spending.

[zaarn]

In git the consensus protocol is "whatever the maintainer thinks is the correct HEAD" or "what the maintainers can agree on to be 'master'". There are many ways you can achieve consensus.