Hash is cryptographic function.
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Knock_Knock_Lemmy_In@lemmy.world 3 months agoGit 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.
uis@lemm.ee 3 months ago
Knock_Knock_Lemmy_In@lemmy.world 3 months ago
A hash function doesn’t check if a signature is valid. Neither does git. Blockchain does check.
saigot@lemmy.ca 3 months ago
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 and thus is vague and variable.
I also don’t think your definition is a very good definition. Do you think git fundamentally changed 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.
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.
Knock_Knock_Lemmy_In@lemmy.world 3 months ago
The phrases used to describe the technology to the public may change, but the technolgical approach doesn’t
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.
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.
No.
Yes. Exactly this.
Optionally is the key word. Blockchain transactions must be signed, and they must be accepted as following the blockchain rules by validators.
Find me a blockchain that doesn’t require signed transactions to make state changes.
I didn’t say anything about modify the chain.
A commit can contain any data it likes. A commit to a blockchain is highly restricted.
cmhe@lemmy.world 3 months ago
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, then you can use git to create a blockchain, by just having that policy.
Knock_Knock_Lemmy_In@lemmy.world 3 months ago
Now add some logic to check whether the actual data is valid (i.e. bob has enough coins in his account to send to Charlie).
Make some incentive to ensure only the main branch survives and forks are either eliminated or merged.
Automate
Now git replicates blockchain’s functionality.
Yes, but add automatically processing the content of the commit for validity and incentives to reduce the number of forks.
Without public key cryptography you just have a hash linked list (like Git).