That little icon above, sold for $7.5 million?
Is the world crazy? Isn't this just a png file?
A thing, if you don't study it seriously, you can't grasp its concept.
Only when you see the details can you get a little grasp.
This article is to show you the details of NFT.
Note: For some very basic things, I will mark "to Xiaobai", and people who know pedestrians can skip it. Some technical things, I will mark "to geek", "to nerd", "to hacker", Xiaobai can skip. Note that these words are compliments, not derogatory, and getting these evaluations is an honor in the eyes of an expert.
Q: I bought an NFT, what did I buy?
A: You purchased ownership of a digital work.
This ownership is recorded on the blockchain.
Note: Ownership is ownership, ownership.
Q: What is recorded on the blockchain, will it record my name, ID number and works?
A: At present, it doesn't. The blockchain only records your address, the number of the NFT work, and the link to the work.
Note that there are three things: 地址、编号、链接.
Q: My address? Do you mean home address?
A: No, it's your blockchain address, which looks like this:
0x40468d172cE354d3fAdAb06D0FA53eDdB2F3AA45
Q: Work number?
A: For example, there is an NFT called Creature, which contains 20 animated images of different shapes. You bought the one with the number 6.
This Creature NFT is an example of a demonstration teaching material from Opensea, which contains some animated images of animals, which can be used for platforms such as games or social networking. Note that when we say NFT, there are two contexts. For example, cypherpunk is an NFT. In fact, it is a set of NFT works with 10,000 punks, and each punk is a specific NFT.
Q: Oh, what does the link to the work look like?
A: It looks like this:
https://Opensea-creatures-api.herokuapp.com/api/creature/6
Note that the 6 in the back is the number of this work.
Note: In addition to this common http(s) link, it can also be an IPFS link.
Q: Open this link and show it to me!
A: I used to think that opening is the image of the work, but it is not.
After opening, the display is this: (You can also open it yourself to see)
{"attributes":[{"trait_type":"base","value":"jellyfish"},{"trait_type":"eyes","value":"joy"},{"trait_type":"mouth","value":"pleased"},{"trait_type":"level","value":2},{"trait_type":"stamina","value":2.3},{"trait_type":"personality","value":"sleepy"},{"display_type":"boost_number","trait_type":"aqua_power","value":10},{"display_type":"boost_percentage","trait_type":"stamina_increase","value":5},{"display_type":"number","trait_type":"generation","value":1}],"description":"Friendly Opensea Creature that enjoys long swims in the ocean.","external_url":"https://example.com/?token_id=6",
"image":"https://storage.googleapis.com/Opensea-prod.appspot.com/creature/6.png",
"name":"Herbie Starbelly"}Don't look at it carefully, the main description is the attributes of this animation, such as this is a jellyfish, the eyes are happy, the mouth is happy, the stamina value is 2.3, the characteristic is love to sleep, its name, description of it, it number, its image, etc.
to hacker: This is the metadata of this NFT, in json format.
I am not interested in these attributes of it. What I am most interested in is what the animal looks like, then I have to look at the image value inside:
image:https://storage.googleapis.com/Opensea-prod.appspot.com/creature/6.png
This is another link, open this link, you can see:
Note: These properties, as well as this work, are not on the blockchain.
On the blockchain, only addresses, numbers and links are saved.
Q: Oh, so simple? Store this on the blockchain?
A: Right. It's that simple.
If I bought Creature's work No. 6, there are only three things recorded on Ethereum:
（0x40468d172cE354d3fAdAb06D0FA53eDdB2F3AA45，6，https://Opensea-creatures-api.herokuapp.com/api/creature/6）
地址，编号，链接That is, the binding relationship of the three elements is recorded .
Note: The address is generated with the private key. With the private key, the NFT bound to this address can be transferred. The private key is only owned by the owner. Anyone without the private key can't touch your NFT.
to hacker: In ERC721, this link is called tokenURI, and the three elements are (address, ID, tokenURI). On the address of the Creature smart contract, by querying your address on the interface, you can know that you have the ID of the NFT, and then get the link of this ID.
to geek: ERC721 is a set of standards for issuing NFTs on Ethereum, which explains what interfaces the NFT contracts should provide, what format the metadata data should be stored in, and so on. Later, there are ERC1155, ERC998, etc. (I feel that these two are more applicable to the game). If you are interested, you can go and see for yourself.
So, technically speaking, an NFT is a record on the blockchain, and the work itself is off-chain.
Q: Are paintings really not on the blockchain?
A: In theory, it can be there, but usually it is not.
Because paintings (music, video, etc. are similar) are relatively large, they take up too much space on the blockchain. (to geek: More importantly, it costs gas to put it on it.)
As Cryptopunks put it:
The actual image of punk is too large (author's note: in fact, 10,000 punks add up to less than 1M) to be stored on the blockchain, so we hashed the set image of all punks and hashed them Values are embedded in smart contracts. You can verify that a punk governed by an Ethereum contract is a real official cypherpunk by computing the SHA256 hash of the punk collection image and comparing it to the hash stored in the contract.
Q: What should I do if the link where the painting is located is invalid?
A: That's a great question.
There are so many things that go wrong with links, because maintaining a website is not easy.
This kind of thing happened, someone bought a music NFT, but the link didn't work, which is a bit embarrassing.
In theory he is still the owner. But to a certain extent, the evidence is gone, who can prove what was originally in that "link"?
What's more, the content in the link can be changed. When I sold it to you, it was an image of a fish. Later, I changed the content in the link to a pig. So do you own the fish or the pig?
This tests the integrity of the issuer.
Q: What else can I do?
A: Consider replacing HTTPS with IPFS.
HTTP(S) is a centralized system and such systems are prone to failure.
So now NFT is more popular to store works on IPFS (a distributed file storage system), which is what the boring ape uses.
The link (tokenURI) for Boring Ape No. 1 is as follows:
ipfs://QmeSjSinHpPnmXmspMjwiXyN6zS4E9zccariGR3jxcaWtq/1
Open this file and its contents are:
{"image":"ipfs://QmPbxeGcXhYQQNgsC6a36dDyYUcHgMLnGKnF8pVFmGsvqi","attributes":[{"trait_type":"Mouth","value":"Grin"},{"trait_type":"Clothes","value":"Vietnam Jacket"},{"trait_type":"Background","value":"Orange"},{"trait_type":"Eyes","value":"Blue Beams"},{"trait_type":"Fur","value":"Robot"}]}The link to the image here is:
ipfs://QmPbxeGcXhYQQNgsC6a36dDyYUcHgMLnGKnF8pVFmGsvqi
Open the file like this:
Q: Cypherpunk has no link at all? Where does that punk image exist?
A: Yes, when Cypherpunk was launched, there was no ERC721, so there was no link (tokenURI) at all.
All 10,000 punks are on its official website at this address:
https://www.larvalabs.com/public/images/cryptopunks/punks.png
The hash value of these 10,000 punk collection images (a total of 848k) is recorded on the blockchain.
to Xiaobai: If you don't understand hash, you can read this article I wrote: If you understand hash , you will understand more than half of the blockchain
If there is a punk that is different from any of the images in this collection, then the punk is fake.
If you buy punk number 1324, only the binding between your address and this number (1324) is recorded on the blockchain, and nothing else.
Q: I'm a novice. I still don't understand what you said. Can you use an analogy to tell me what NFT is?
A: For example: V's family has released a limited number of bags, 10,000 (each bag may be different, or it may be the same bag, just the number is different).
You go shopping, buy number 23, and leave your home address. Then, 你家地址、23号、包包链接it will be recorded on V's ledger.
Previously, this record was recorded on paper ledgers, later, in the database of the information system, and now, it is recorded on the blockchain.
If someone says he owns number 23, not you. You can go to court, and you can check the blockchain ledger. The ledger says that the address bound to the No. 23 bag is Room 806, Building 19, a certain community in Beijing.
Under the supervision of the court, you and your group came to the door of this house. He couldn't open the door, but you took out the key and opened it, which proved that you are the real owner.
And V's bags are digital and placed on the ledger where the link points to. (I won't make an analogy for this, everyone knows it)
Q: It turns out that NFT is just this, so does it make sense for me to buy an NFT?
A: There are at least the following 3 points:
1. You can show off. You can say, I also have NFTs. If someone asks you what you bought, you say that I have a unique thing, or that I have one of the 10,000 "bags" that are limited to the world.
2. If someone says you don't, you can prove it to him. For example, you can show him on Opensea, or you can show him on the NFT's website. For technical nerd, you can show him on etherscan.
The NFTs (officially called "digital collections") bought through the fans on Alipay can be viewed on Alipay.
3. If this NFT appreciates in the future, you can sell it to make money. (Note that most NFTs in China are not allowed to be sold to prevent speculation)
For each transaction of works on Opensea, the platform will take a cut (such as 2.5%), and for each subsequent transfer, the original author can get a pre-set share ratio, such as 1/10.
Q: Buying an NFT on the platform is not much different from buying digital goods on Taobao. What is the advanced point of this?
A: The advanced thing about NFT is that it uses blockchain technology, and blockchain is advanced.
The blockchain is advanced in: security, openness and transparency, and tamper resistance.
NFT uses blockchain, which makes it different from Taobao digital goods in at least 3 points:
1. NFT is a pure digital product, the transaction is highly automated, and all transactions cannot be tampered with. What is yours will not belong to others. (Many people are indispensable in Taobao's transaction process, and it is not impossible to change)
2. No one can control in the background, there is no insider, no black box operation, and all data are clearly publicized. (Taobao background code and data will not be shown to you)
3. Due to the ability of smart contracts, many things that could not be done before can be innovated.
Cypherpunk's official website says this:
“We write code that lives on the blockchain that anyone can use to buy and sell punks with any other person in the world. One of the interesting things about this system is that we no longer control the code that runs the cypherpunks! Once we publish it on the blockchain, it's permanently embedded there and no one can modify it. It's scary for us as developers because we worry about bugs. But not being able to modify the code is very Powerful, it allows users to verify that there are really only 10,000 punks, verify that we cannot steal any of the punks from you, and ensure that what we claim is true. Cypherpunks are created and run on the ethereum network, code in control Ownership. After that, we no longer have creative or ownership control.”
Q: So how do I make an NFT?
A: Casting (mint).
To make an artwork into NFT is to cast it into NFT.
The so-called casting is to record those three elements on the blockchain.
On Opensea, it's usually minted to one's own address and then transferred to someone else's address through a transaction.
There are also many NFTs that allow users to mint, so that users can directly mint to their own addresses. (like the boring ape)
Q: The so-called existence on the blockchain mainly refers to which blockchains?
A: As long as it is a blockchain that supports smart contracts, such as: Ethereum, BSC, Polygon, Tron, EOS, Flow, Conflux, Nervos, etc.
Ali's NFT exists on the "Ant Chain", and Tencent's NFT exists on the "Zhixin Chain", but these are more alliance chains.
Globally, more NFT issuers still prefer to mint on Ethereum. After all, Ethereum is the biggest, most famous, and looks the most secure.
Q: Even if it is valuable, it won't be so hot.
A: Blockchain and smart contracts are leading the way.
Anything that sets a trend will be hot for at least a while.
Revolutionary things will be popular for decades, such as the Internet since 1973 (more ARPANET before), from 1994 to 2014, at least 20 years. The blockchain has been around since 2009, and it is estimated that it will become popular in 2029, and it is still just a prelude.
Our world is becoming Internet-enabled, as everyone has seen.
In the future, our world will be blockchainized.
This judgment is based on the assertion that "the world is going digital." The cornerstones of digitization are security, trustworthiness, and automation, and blockchain provides them all.
A lot of big events, "just like a toy in the beginning." 1
Q: Why is cypherpunk so expensive?
A: In a nutshell, one is that it is interesting in itself, the other is that it has formed a great reputation effect, and the third is that it has developed investment value because of the first two points.
1. There are two points in its name, crypto and punk, which make geek want to have one. Crypto is a symbol of freedom, mystery, anti-mainstream, digital power; punk is cool, cool, cynical, simple and casual; each punk is automatically generated by the computer, which is in line with the hacker way of doing things; 24*24 pixels are provocative. A retro geek feeling.
2. Cypherpunk may not be the first NFT, but the first well-known NFT. The circle became popular first, and some blockchain players and executives of technology companies took the lead in purchasing Punk, taking pride in it and enhancing its digital prestige. Then go out of the circle and set off a trend.
3. At this stage, people who buy punk again basically enter with an investment psychology, in order to sell it in the future.
CryptoPunk was created in June 2017, when the concept of NFT was not fully established, and there was no market. Larva Labs originally planned to make a batch of avatars for mobile apps or games, so it generated 10,000 24 x 24 pixel 8-bit avatars based on an algorithm, each with its own randomly generated unique punk appearance and characteristics. But when it was sold, no one cared.
So they changed their minds, kept 1,000 avatars for themselves, and distributed the remaining 9,000 for free. Anyone with an Ethereum wallet can get them by themselves, and all the avatars were quickly snatched up. After players get the avatar, they can freely resell it. Just like BTC, CryptoPunk, which was born out of nowhere, has a leader-like status in the NFT field.
Q: How can Beeple's "Everydays: The First 5000 Days" be so expensive?
A: Consider two points:
1. There are 5000 works in it.
2. The buyer is the anonymous founder of the NFT fund Metapurse (pseudonym Metakovan).
Q: I can't afford avatars like cypherpunk and boring ape. However, can't I use it if I don't buy it?
A: You can use it, but you are not the real avatar owner, which may bring the following problems:
1. You are using someone else's work without authorization. In theory, you may be infringing, although usually no one will pursue it.
2. If you use him as an avatar, you may be a little embarrassed when others question him. Because the consensus in the field of NFT avatars is: you can only make an avatar if you have it.
Also, it is technically easy to prove whether someone has an NFT or not, and Twitter recently planned to use technology to mark whether an NFT avatar is real.
Chain news, Twitter consumer marketing director Justin Taylor released a video [ twitter], showing a new feature that has not yet been released: users can set NFT Twitter personal avatar. In the video display, the user enters the page for editing personal information, clicks on the avatar, enters "Select NFT", then connects to the corresponding encrypted wallet (the video display includes Coinbase Wallet, Trust, MetaMask, etc.), and then selects the corresponding NFT work, namely Complete the profile picture setting. There will be an Ethereum logo in the upper and lower right corner of the avatar to indicate that this is true 2 .
And the NFT collections sold on Alipay can be made into payment code skins. If you buy a fake one from "Salt Fish", you cannot make skins.
In short, everything is transparent, and if you use it without owning it, it will be revealing, and you will not enjoy that real sense of ostentation.
Q: Do all NFTs have to be sold on the trading platform?
A: In most cases this is the case.
However, some NFTs have their own website where they can be bought, such as Cypherpunk's website:
https://www.larvalabs.com/cryptopunks
You can also sell offline, as long as you have the right channel. For example, Beeple's "Everydays: The First 5000 Days" was sold through Christie's auction.
Q: What trading platforms are there?
A: Such as Opensea, Rarible, SuperRare, AtomicMarket, Nifty Gateway, there are many.
In China, there are Ant Chain fan particles, Tencent's Magic Core, NFT China, Secret Treasure and so on. (Most can only buy but not sell)
The most well-known in the world is Opensea.
Q: It makes me want to buy a punk, how can I buy it?
A: Go to Cypherpunk's official website to buy it, don't go to Opensea to buy it (there may be fakes there).
You have to have a wallet, like Metamask.
After connecting to the wallet, you can see the buy and bid buttons for the punk being sold:
If you do buy it, you also need to have Ether.
Q: I am not a technician, how do I mint an NFT?
A: You can mint one on a trading platform, such as Opensea.
Blockchain application websites like Opensea are all authenticated by wallet (to hacker: the bottom layer is authenticated by the public key encryption system), and the browser needs to install the wallet plug-in (used to manage the public and private keys) to complete the login. This article does not intend to introduce wallet download and use methods, you can search by yourself.
When you log in to Opensea through Little Fox,
Click Create to mint NFT.
As a test, I uploaded a photo I took during the Mid-Autumn Festival in 2021. After the casting is successful, it will show some details:
to nerd: Note that this complies with the ERC-1155 standard. On the Polygon blockchain, note that the TokenID is very large, which shows how ambitious Opensea is.
Then click the "sell" button, after a series of operations, the platform displays:
This NFT can be traded on the platform, and the historical transaction information about this NFT will also be displayed:
Q: Is it that simple? Seeing that I was on the verge of moving, I went to the Internet to find a beautiful painting and made it into an NFT, okay?
A: This requires copyright awareness. Otherwise, it may lead to a lawsuit.
For example, if you want to cast an NFT of an oil painting, but the painting was not drawn by you, the author must authorize you to cast the NFT before you can do so.
Otherwise, the author comes to you, how should you face it?
Q: Can you tell me about the relationship between NFT and copyright?
A: Wait for me, the next one.
Text｜Wei Jianvan
The next big thing will start out looking like a toy.(https://cdixon.org/2010/01/03/the-next-big-thing-will-start-out-looking-like-a-toy)
Twitter NFT verification is coming!（https://www.youtube.com/watch?v=NdBxkzxuBXg）