Development technology sharing of Jingtan NFT digital collection system

2021 3 month , social media “ twitter ”（Twitter） Co founder and CEO jack · Dorsey （Jack Dorsey） First tweet sent （ Below ） Auctioned in the form of non-homogeneous tokens （NFT）, In the end to 2021 6 Month after month 290 Sold for more than $million .

Sotheby's auction house in New York 1175 Sold a pixel art style encrypted punk for $million 752335 Photos of the （ The figure below ）, More and more companies are flocking to the circuit .

some NFT The transaction price of digital goods is unimaginable . Is it worth money or hot money ？ I personally understand , The recognition of the value of artistic works will bring a lot of subjective colors . Different people will see if it is worth the money . As a technical practitioner of blockchain , I'm more concerned NFT：NFT What is it NFT How it is stored in smart contracts NFT What is the expansion direction of Technology
NFT What is it

NFT（Non-Fungible Token）, This actually means non-homogeneous tokens . The assets represented behind each tag are different 、 Indivisible . In the real world , Different works of art and different design schemes , These assets are indivisible , The corresponding values behind them are also different NFT Can better carry these values NFT It can be understood as a specific asset registration method based on blockchain . Combine the transparency and tamper resistance of blockchain , It is easy to identify the creators and holders of assets . Combined with smart contract , It can ensure that only asset holders have the right to operate assets in the smart contract storage mode
NFT The earliest known project is 2017 Developed by Ethereum based larva lab in cryptopunks project . There were no standards NFT agreement . You can view the relevant smart contract codes at the following address ,https:
etherscan.ioaddress0xb47e3cd837ddf8e4c57f05d70ab865de6e193bbb#code . Some of the codes are as follows ：

In the initialization code , Defined CryptoPunk. Stored on the chain 10000 Image hashes , from ：
10000 An avatar . Through the hash chain , The corresponding position and specific content of each avatar cannot be changed at will . Once changed , The newly generated image hash and the hash in the smart contract will not reach an agreement ：

10000 A head , The holder address of each avatar is saved in the above mapping ：

When operating each avatar , You will check whether the operator is the holder of the avatar in combination with the above

, We can observe that , The content of each avatar in the encrypted punk project is certain , And you can also find the holder of each avatar . After smart contract processing , It is easy to locate the address of the holder behind each digital asset , And the ownership relationship is clear . meanwhile , And NFT The corresponding digital assets can be appreciated by everyone . Creative sharing , But the ownership relationship is clear , The right to manage assets is in the hands of the asset holders

2018 year , With the popularity of encryption cat , Put forward erc721NFT agreement （ For details, see https:
eips.ethereum.orgEIPSeip-721 ）. The agreement defines 721 The interface specification , It specifies the functions that the smart contract and some optional implementations must implement

2021, Started another based on erc721 Standardized larva laboratory project meebits（ See the specific contents of the contract ：https:
etherscan.ioaddress0x7bd29408f11d2bfc23c34f18275bbf23bb716bc7#code）, Some codes are as follows ：

In this release ,NFT Relevant content is stored in IPFs in ：

Each... Is defined here meebits The specific content represented . for example , We turn on https:
meebits.larvalabs.commeebit1：

The above content corresponds to each meebits External representation and unique properties of . From the smart contract, we can find , Chains usually store hashes to ensure the invariance of assets . meanwhile , The service layer will provide a specific style of asset display

Combined with the above code , We found that the release a35 It is not difficult , But the point is 35 The value behind ： That's a good idea 、 Excellent solutions, etc . Interested students can consider how to do it in the existing NFT Simplified on the basis of the agreement NFT Implementation of blind box distribution

NFT Technology extension

With NFT The application ecology of is increasingly abundant , People are also expecting its technical capabilities to meet more application scenarios , for example NFT Can it be split ？ User purchase NFT Can you support personalized creation ？
1.NFT Split ：

NFT It is indivisible in itself . To split , You can lock NFT assets , Then, based on this asset, a specific separable NFT assets , Let more people share art , Make its value flow more flexible and efficient .

Interested students can refer to the following smart contracts ：https://etherscan.io/address/0x85aa7f78bdb2de8f3e0c0010d99ad5853ffcfc63#code. Part of the code is as follows ：

The above code implements a new agent contract to handle distribution ERC20 The token of the agreement , At the same time, the corresponding ERC721 Transfer of assets to agency contracts ：

The above code ensures that if the user needs to extract the corresponding NFT When assets , It is necessary to hold all the corresponding issues ERC20, And destroy .
2.NFT Second creation ：

NFT Digital asset holders , Can I NFT Second creation on ? Based on the tamper proof feature of blockchain , Generated NFT It can't be modified , But users can be based on the original NFT To recast new NFT. Referable 【1.NFT Split 】, Put the original NFT Locked in the contract layer , Then based on it to create new NFT. Users can also remove the secondary creation part , Restore NFT To do the circulation trade .
Conclusion ：

Blockchain based NFT agreement , Turn the information flow of the digital world into a value flow . Data is the most important production factor of information internet , To give full play to its application value , We should not only pay attention to the protection of the rights and interests of data owners , Also focus on how data assets can be more flexible 、 Freer circulation .