The blockchain is essentially a linked list
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The only major difference is that Git is a DAG while a blockchain is restricted to being a tree.
What do they have in common?
A block is a commit, containing a metadata and a hash pointing to the preceding commit.
A Merkle tree is a tree, though restricted to having only two children; trees in Git also contain the hashes of its children.
A transaction is a blob, the new file to be included in the next commit.
And if I recall correctly, the Git protocol was devised against a similar issue of centralization - SVNs. If the SVN could not be reached, then you were not able to access your repository. Since there was only one ledger, it meant a single point of failure.
Out of curiosity, I wonder if there's a reason why it's not just built on top of git? Is there an inherent incompatibility between the two, or some sort of benefit to forgoing using existing tech?
In addition, the protocol of blockchain is way more complex than the one for Git; you have concepts like proof of work and economic problems like double spend that have to be dealt with.
>> "As the image shows, all the nodes are connected to each other."
He is confused between a block-chain and the computing nodes in a network.
I did not know that Quora did or allowed that. Did the writer remove it? Did it get down voted to oblivion (unlikely, had positive up votes yesterday)? Seems un-transparent.
Edit: Just kidding, obviously singley.
I am not a blockchain expert but don't agree with the "not at all" answer. The illustration seems misleading, the nodes have nothing to do with the data structure, AFAIK blocks are only linked to previous block.
I've always understood it as essentially a singly linked list where no list node can be removed without invalidating the entire list.
Am I wrong?
Over simplifications that gloss over important details
Fighting imposter products may have extremely valuable applications for blockchain, for example knock-off Gucci bags etc. It'll take years before authoritative systems emerge that dominate that product validation space, but it's probably inevitable that they will.
This example always gets brought up but Gucci bags already come with serial numbers and receipts that you can use for lookups and registration with Gucci. Presumably Gucci is using a database to store this information. What benefit would consumers realize if Gucci changed out their database for one that was immutable? Is there really any significant number of Gucci consumers who don’t trust the company to maintain the integrity of the product database they currently use? The interests of the company and their customers seem pretty aligned. Perhaps there would be some benefit to having the full sales database easily and instantly accessible by anyone in the world? But absent any demand from consumers for them to go farther than they already have that would seem to be outweighed by Gucci’s desire to not reveal all of their sales data to competitors (or GDPR-busting private information for that matter).
If they did want to give up such detailed information then why not just provide weekly sql dumps on the web and avoid the consultant fees and expense of maintaining a more inefficient database? Perhaps they could also make customers sign a contract that prevents hem from engageing in private sales without registering the sale with GucciCentral. The fact they have never taken a simple steps like these to dispell any trust issues between them and their customers tells me that there may not be many that their current systems don’t already address adequately.
Please tell me if I’m missing something. This one has puzzled me for years.
1) The problem domain doesn't need decentralization. If there is a trusted central authority then a cryptographically signed git database suffices.
2) There is no economic incentive for mining. With Bitcoin, there is an incentive for miners to spend significant amounts of electricity and computational power competing to add blocks to the blockchain, since they are rewarded with newly minted coins and transaction fees. The security of the whole network depends on this being a very expensive process because the more costly it is to add a new block to the ed of the chain, the more costly it will be for a malicious adversary to construct an alternate blockchain history (to perform double spend attacks and more). Non-currency blockchain solutions can't award in-chain rewards to the miners so an offchain inentive must be found (which is extra tricky if you follow rule 1 and assume that the network participants do not trust each other)
They're neither append-only, nor are they ledgers (which are basically just logs, nowhere in the definition of which is there an implied reference to any other item).