The cryptography has much simpler algebraic analogues - what we are looking for is a “one-way function”. This means a mathematical symbol that only works on the left side of the equals. The simplest one is the remainder of a division. For example if I told you that I had a remainder of 5 after dividing by 20, you wouldn’t know if the original numerator was 25, 45, 65, 85, and so on. This operator is called mod (modulus). Even if you don’t know what value I started with, It’s not hard to guess what possible numerators could be with modulus. That’s where the cryptography comes into play: a cryptographic hash is designed so that it’s practically impossible to guess the original numerator. We’ll stick with the modulus for explanatory purposes, but imagine that you can’t list off possible numerators like I did.
Now we can invent a puzzle for a computer to solve. We’ll start off with the same values as before, but - again - we are disallowing easy guesses. This forces us to check 1 mod 20, 2 mod 20, 3 mod 20, 4 mod 20, 5 mod 20 and so on. Eventually we’ll hit 25 mod 20 giving us the solution to X mod 20 = 25. Now you can go back to the person that gave you the puzzle and prove that you’ve done 25 steps of work to arrive at a solution (or have made a lucky 1/25 guess). This is called “proof of work”. A cryptographic has consists of a certain number of bits, such as 256 bits - this means a series of 1’ s and 0’s 256 long. The puzzle presented to the computer is “find the numerator that results in the first 50 bits being zero” (the more bits are required to be zero, the longer it will take to find the answer). Because of the incredibly slim chance of guessing the correct numerator, it doesn’t really matter if the computer counts up (like we did with modulus) or guesses. So, in practice, everybody trying to find the solution starts at a random number and starts counting, or trying other random numbers, until someone wins the jackpot. It’s basically a lottery, but the correct numbers have to be discovered instead of being dropped out of a glass ball at the end of the week. Once a computer finds a solution, everybody else playing the game can check their numerator.
Now we can use this lottery to create a blockchain. We start with 5 things: a globally agreed on solution we are looking for (789), an initial block (which is just a number - lets say 12345), Bob’s account #5 of $100, and Sally’s account #6 of $200, and a huge amount of players of the above game. Sally wants to transfer $20 to Bob, so she says to all the players: “I’m #6 and want to give #5 $20. There’s a $1 prize for finding a new block for me.” All the players make a new denominator, by placing the numbers next to eachother - so 12345 6 200 5 100 20 1 - or just 1234562005100201. All the players start trying to find the number that will result in 789. Eventually someone finds 1234562005100990 after a lot of work/guesses. Everybody checks their work 1234562005100990 mod 1234562005100201 = 789. The winning player receives their prize, and now everybody has a new block to start from: 1234562005100201 1234562005100990. Next time someone wants to send some money they will use 12345620051002011234562005100990 as the initial block instead of 12345. Hence, we have set up a chain starting with:
12345 -> 12345620051002011234562005100990 -> …
There’s your block…chain.
Zuberi@lemmy.dbzer0.com 3 months ago
One is the tech, the other is an example of a type of the tech. A square is a rectangle, but a rectangle is not a square.
For most applications, this isn’t necessary:
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There are some examples like in biotech/finance that I personally believe will require a blockchain to be truly “fair” at the end
FiniteBanjo@lemmy.today 3 months ago
I like this flowchart but honestly most third party data handling solutions are just asking for a major breach: stoking vulnerable people over the coals.
Zuberi@lemmy.dbzer0.com 3 months ago
Ignore the FBI hack, and the SEC hack, and the DoD hack, and the FINRA hack, and the…
Knock_Knock_Lemmy_In@lemmy.world 3 months ago
Diagram is missing a “do records need to interact” control box.
Dnn@lemmy.world 3 months ago
Now add that trustlessness is impossible and you can scratch the blockchain box for good.
You cannot get rid of trust in some form. You need entry to the system, so you need to trust its gateway. You need to trust the network to not have some vulnerability like a 50% attack. And eventually you need to trust the developers not to add critical bugs (that alone is virtually impossible) or pull off some scam.
HopFlop@discuss.tchncs.de 3 months ago
The solution to the requirement of minimal trust is not to just give up on and trust few peopme with everything. 50% attacks in large networks are next to impossible.
PropaGandalf@lemmy.world 3 months ago
Well in decentralized, autonomous (user run) systems you have actually 0 trust.
daltotron@lemmy.world 3 months ago
I’m stupid, can you give me a like, more clear practical example of a good use of blockchain? Cause I get the sense that a good amount of this conflict, going off that flowchart, is going to be due to the evaluation of these situations as like, not needing to arise in the first place, or maybe like, a philosophical objection to the necessity of the technology, maybe. But I think a clearer example could help with this.
Dnn@lemmy.world 3 months ago
Do you see how all the answers are generic, tend to be long and read like a sales pitch? That’s because the actual answer is: no, there is no practical legal application that isn’t better solved with conventional tech.
The only application that is successfully used in practice is paying for organized crime: buying goods and services on the dark web and paying for extortion like ransomware attacks.
Knock_Knock_Lemmy_In@lemmy.world 3 months ago
blockworks.co/…/nft-airline-tickets-revolutionize…
Zuberi@lemmy.dbzer0.com 3 months ago
*Blockchain technology can improve health care services in a decentralized, tamper-proof, transparent, and secure manner. *
This can also be used for research institutes to be able to research with each others’ findings.
Here is a paper on the topic: www.ncbi.nlm.nih.gov/pmc/articles/PMC8555946/
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Blockchains are also great for the verification of digital goods as tangible assets. While I’m not sure we reach this level of meme ^, people could 100% mint their own house’s deed and trade that as a legit way to buy/sell their house.
I am very carefully avoiding the words “NFT” because they are another horrible use-case of a blockchain (and a prime example of how capitalists turn a good tech into something stupid for a quick buck), but this would theoretically be a tokenized-security with a 1:1 to the actual deed to the house.
Is that more secure than the normal process of buying a house? Do you really need it to be external to a 3rd party when the transfer of homes already exists? No not really lol, hence why we probably see it the most in highly regulated industries like biotech and finance first.
HIPPA/Securities-laws (or lack-thereof) will require a tough regulatory framework that “could” realistically be done via a 3rd party, but you have to ask yourself if you trust big-pharma and wallstreet enough to regulate themselves like that.
daltotron@lemmy.world 3 months ago
I just wrote out another comment, and I think I kinda figured out my core question, but, is there a way to save my medical information without doxxing myself, if this is supposed to be like, a public database, you know, if that’s kinda the point, is that everyone can look at everyone else’s stuff? I got the impression that a lot of the current blockchain stuff wasn’t capable of the necessary levels of storage that would be required for like, health records, on their own.
I dunno, maybe you could have some situation where you have a key, that opens up some cryptography on the blockchain, and that blockchain piece when unlocked gives you another key that lets you access your medical records, or something like that, and that might be able to fit. But, then, I don’t really see how that’s any different from just having like, the key to the person’s medical records be contingent on person. Like biometric security, or government ID, or something.
Point out wherever I’ve made wrong assumptions here, I’m just kind of talking out my ass, and hoping that I’m correct inso that the conversation can continue and I can scrape more out of it, I don’t really expect to be right.
OneOrTheOtherDontAskMe@lemmy.world 3 months ago
No no, thank you for this.
I understand blockchain as a concept, and kind of hownit plays into cryptocurrency, but understanding a true example of blockchain use outside of finances is something I needed more info on, thank you
dtjones@lemmy.world 3 months ago
The blockchain is essentially a ledger that tracks transactions (including the creation of currency). One thing that is not always clear is how important it is for a blockchain to be decentralized. When I say “decentralized,” I mean that many different people are operating a server that performs transactions on a larger network. These people are rewarded in currency for their efforts, and are sometimes referred to as “miners,” though this term is changing somewhat.
There are thousands of these servers in a network that are operating on and tracking the ledger for blockchains like Bitcoin or Ethereum. Any updates to the ledger are verified by all of these nodes. As long as 51% of nodes can verify a transaction, it will be added to the ledger. This means that as long as someone doesn’t own 51% of the network, they can’t just inject whatever transactions they want (i.e., fraudulent activity). In practice, this makes these networks very resilient to fraud.
I think this paves the way for a lot of the practical examples you’re looking for. For example, there’s no way for the network to decide to just give tons of money to a single entity for some “economic policy” like Too Big to Fail (i.e., corporate bailouts). This means you don’t have to wake up one morning worrying about whether or not your currency will rapidly inflate because of things like corruption. Another example is the true ownership of digital assets. NFTs have (rightly) gotten a lot of flack for being overpriced JPEGs, but there are real use cases here. A random middleman can’t just decide to price gouge because they own all the tickets first (Ticketmaster). Instead, artists can mint tickets on the blockchain (very important: this ensures authenticity) and then fans can buy them on the blockchain - no middle man required. You still show a QR code at the door for verification like you would now.
daltotron@lemmy.world 3 months ago
Could like, 51% of the owners just coordinate to kind of, do a fraud? I mean it sounds like an inherently democratic system, but from what I’ve understood of, say, miners, right (dunno how this works for proof of stake, but I imagine it has similar problems), those rigs are gonna be bought by people who disproportionately have higher earnings and can afford more GPUs in finland or wherever, and then that’s going to just kinda recreate the same power dynamic that we see in the real world already. Which ends up in the same kind of speculative market garbage we have with stock ownership in companies already.
I also don’t really understand how a ticketing system would really work on the blockchain. I probably don’t know enough about cryptography to know how it might work, but I got the sense that nfts weren’t even overpriced jpegs, they were overpriced links with pseudo-legal contracts, that were still prone to link rot, and didn’t really indicate any IP ownership. If you had a code on the ticket instead that could only be verified as real, rather than fake, by a ticketing person, instead of like, a link, that would probably be the use case, right? am I getting that correct, is that something cryptography can do? probably, right?
Also, can someone just like, steal your ticket still? Or like impersonate you as the ticket guy, or what? Like from the others have told me and also just from what I know already, you can’t really change the chain unless, like you said, you have 51% of the owners, so how would you be able to like, put something in the chain that identifies the owner as being the owner? Wouldn’t it be more secure to have just like, a verifiable code or something, that you can delete, that isn’t public, between the artist and the buyer? Then you could ensure anonymity between the buyer and the venue and stuff, you could work in establishing characteristics like oh here’s my driver’s license, here’s my government ID, without putting that stuff on the blockchain, which seems like a bad idea.
profdc9@lemmy.world 3 months ago
A blockchain can provide an irrevocable record, and it can provide a mechanism for uncooperating parties to agree that the record should be created. This is usually used for financial transactions involving coins of dubious value, but it can also be used for recording transactions of real world assets as long as those transactions can be faithfully linked to the event on the blockchain. Therefore the blockchain doesn’t really prove that a transaction is fraudulent or not, all it proves is that a sufficient number of parties believe it is not.
daltotron@lemmy.world 3 months ago
That kind of seems like the big glaring video game boss style weak point, to me. I feel like you’d still need some external third party to verify that everything is properly linked up to the blockchain, or like, someone could just impersonate someone else through whatever things are used to link something to the blockchain, and then it’s just kinda back to square one, I would think. I dunno, I think also maybe I just don’t really quite get it.
far_university1990@feddit.de 3 months ago
git-scm.com
__dev@lemmy.world 3 months ago
Git is not a blockchain. There is no distributed ledger; no consensus algorithm.