Bitcoin payment
NFT (Non Fungible Token) 是一种基于区块链技术的数字货币，只不过相对于比特币的无差别、可互换(就像每张毛爷爷都一摸一样），每一件 NFT 都是独一无二的。比如说，这个世界上只存在一条 Jack Dorsey 于 2006 年 3 月 22 日 4 点 50 分发出的推特，将其制作为 NFT 后，除了其本身，再没有绝对意义上与其等价的物品。（相当于每一张毛爷爷都是独一无二的纪念币）
互联网时代的一切都能够通过复制粘贴，拷贝出无数份，而 NFT 则制造出一种人为的稀缺，并通过这种稀缺获得价值。换句话说，NFT 不仅包括作品本身，更附带有无法伪造的创作者认证信息，稍微类似于亲笔签名。买家购买的不是作品的版权或是使用权，而是能够证明「我确实买了这么个东西」的数字凭证。所以NFT的收藏价值被各路投机者所看好。
Imagine that you need to sell a house. It’s a rather complicated and daunting process which entails a lot of paperwork, communication with different firms and people as well as a high levels of various risks. That’s why the absolute majority of house sellers decide to find an estate agent, who deals with all the paperwork, markets the property and acts as an intermediary when the negotiations begin, overseeing the deal until it’s closed.
Moreover, the agency provides an escrow service, which is especially useful in such transactions, as the sums involved are normally quite big and you can’t really fully trust the person you will be dealing with. Nevertheless, after the successful deal, the seller’s and the buyer’s agents will share around seven percent of the sale price as their commission. This amounts to quite a substantial financial loss for the seller.
It’s situations like this where smart contracts could really come in handy and effectively revolutionize an entire industry, all the while making the process a lot less of a burden. Perhaps most importantly, they would solve a trust issue. Smart contracts work on an ‘If-Then’ principle, which means that the ownership of the house will be passed on to the buyer only when the agreed upon amount of money is sent to the system.
They also work as escrow services, meaning that both the money and the ownership right will be stored in the system and distributed to the participating parties at exactly the same time. Moreover, the transaction is witnessed and verified by hundreds of people, so the faultless delivery is guaranteed. As trust between the parties is no longer an issue, there is no need for an intermediary. All the functions that an estate agent does can be pre-programmed into a smart contract, while simultaneously saving both the seller and the buyer considerable amounts of money.
And this is just one example of potential uses of smart contracts. They are capable of facilitating an exchange of money, property and anything else of value, ensuring the complete transparency, avoiding the services and accompanying charges of a middleman and eradicating the question of trust between the parties. The code of a particular smart contract includes all the terms and conditions agreed upon by the parties, and the information about the transaction itself is recorded in a Blockchain, a decentralized, distributed public ledger.
Simply put, smart contracts work a lot like vending machines. You just drop a required amount of a cryptocurrency into the smart contract, and your escrow, house ownership right, driver’s license, or whatever else drops into your account. All the rules and penalties are not only pre-defined by smart contracts but are also enforced by them.
A smart contract can work on its own, but it can also be implemented along with any number of other smart contracts. They can be set up in a way when they’ll be dependant on one another. For example, successful completion of one particular smart contract can trigger the start of another one, and so on. In theory, whole systems and organizations can run entirely on smart contracts. To some extent, this is already implemented in various cryptocurrency systems, where all the laws are pre-defined and because of that, the network itself can function autonomously and independently.
Essentially, there are three integral parts, also referred to as objects, to every smart contract. The first one is signatories, the two or more parties using the smart contract, agreeing or disagreeing with the terms of the agreement using digital signatures.
The second object is the subject of the agreement. This can only be an object that exists within the smart contract’s environment. Alternatively, the smart contracts have to have unhindered and direct access to the object. Even though the smart contracts were first discussed back in 1996, it was this particular object that stalled their development. This problem was partially solved only after the first cryptocurrency appeared in 2009.
Finally, any smart contract has to include specific terms. Those terms need to be mathematically described in full and using a programming language that is appropriate for the particular smart contract’s environment. This includes the requirements expected from all the participating parties as well as all the rules, rewards and punishments associated with said terms.
In order for them to exist and function properly, smart contracts have to operate within a specific suitable environment. First of all, the environment needs to support the use of public-key cryptography, which enables users to sign off for the transaction using their unique, specially generated cryptographic codes. This is the exact system that the absolute majority of currently existing cryptocurrencies is using.
Secondly, they require an open and decentralized database, which all parties of the contract can fully trust and which are fully automated. Moreover, the entire environment itself has to be decentralized for the smart contract to be implemented. Blockchains, especially the Ethereum Blockchain, are the perfect environments for smart contracts.
Finally, the source of digital data used by the smart contract has to be completely reliable. This entails the use of root SSL security certificates, HTTPS, and other secure-connection protocols that are already being widely used and are being implemented automatically on most modern-day software.
Autonomy — Smart contracts eradicate the need for a third-party intermediary of facilitator, essentially giving you full control of the agreement.
Trust — No one can steal or lose any of your documents, as they are encrypted and safely stored on a secured, shared ledger. Moreover, you don’t have to trust people you’re dealing with or expect them to trust you, as the unbiased system of smart contracts essentially replaces trust.
Savings — Notaries, estate agents, advisors, assistance and many other intermediaries are not needed thanks to smart contracts. And, by extension, the extortionate fees associated with their services.
Safety — If implemented correctly, smart contracts are extremely difficult to hack. Moreover, perfect environments for smart contracts are protected with complex cryptography, which will keep your documents safe.
Efficiency — With smart contracts you will be saving a lot of time, normally wasted on manually processing heaps of paper documents, sending or transporting them to specific places, etc.
Read more: How Blockchain Technology Works
Smart contracts were first described by Nick Szabo, a computer scientist and cryptographer, in 1996. Over the course of several years, Szabo reworked the concept and released several publications, where he described the concept of establishing contract law related business practices through the design of electronic commerce protocols between strangers on the Internet.
However, the implementation of smart contracts didn’t happen until 2009, when the first cryptocurrency Bitcoin appeared along with its Blockchain, which finally provided a suitable environment for smart contracts. Interestingly enough, Nick Szabo designed a mechanism for a decentralized digital currency called Bit Gold in 1998. It was never implemented, but it already had many of the features that Bitcoin boasted about 10 years later.
These days, smart contracts are mainly associated with cryptocurrencies. Moreover, it is fair to say that one could not exist without the other, and vice versa, as decentralized cryptocurrency protocols are essentially smart contracts with decentralized security and encryption. They are widely used in most of the currently existing cryptocurrency networks and are the prominent and one of the most hyped features of Ethereum.
Read more: What is Ethereum
While the stance of governments, financial regulators and banks worldwide on cryptocurrencies has been ranging from extremely cautious to carefully accepting, the technology behind them – Blockchain and smart contracts – has been widely accepted as revolutionary and it is being implemented across all levels.
For example, just recently, the Depository Trust and Clearing Corporation (DTCC) and four major banks – Bank of America Merrill Lynch, Citi, Credit Suisse and J.P. Morgan – successfully traded credit default swaps on the Blockchain developed by Axoni, using smart contracts. The smart contract used held information such as individual trade details and counterparts risk metrics, which, according to a press release, provided a new level of transparency for partners and regulators.
Similar things are happening everywhere. This month, a consortium of 61 Japanese and South Korean banks has been testing Ripple’s Blockchain and smart contracts to enable cross-border money transfers between the two nations. The new system will roll-out in 2018. Even Sberbank, a Russian government-controlled bank, in a country which has been notoriously anti-cryptocurrency, the Ethereum’s Blockchain and the smart contracts enabled by it are being tested.
The tests came in light of Sberbank joining the Enterprise Ethereum Alliance, a consortium of more than 100 businesses, including top players such as Cisco, BP, ING, Microsoft and so on. The Alliance aims to develop a Blockchain fine-tuned for business-use, where smart contracts needed for particular companies can be developed and implemented.
As smart contracts were developed in association with cryptocurrencies, they are still mostly being implemented into the world of finance and banking. Nevertheless, this technology can be used by governments worldwide to make the voting system more accessible and transparent. Supply chains can use it to both monitor the goods and automate all the tasks and payments involved. Real estate, healthcare, taxes, insurance and countless other industries can benefit from the implementation of smart contracts and the benefits they have to offer.
Smart contracts are an extremely young technology. Despite having a lot of promise, it is still can be prone to problems. For instance, the code that makes up the contract has to be perfect and contain no bugs. This can lead to mistakes and, sometimes, to such bugs being exploited by scammers. As was the case with The DAO hack, money put into a smart account with a mistake in its code can be stolen from it.
Moreover, the novelty of the technology still bring a lot of questions to the table. How will the government decide to regulate such contracts? How will they be taxed? What happens if the contract can’t get access to the subject of the agreement, or anything unexpected happens to it? It this was to happen when a traditional contract was made, it could be rescinded in court, but the Blockchain makes the contract perform no matter what, in accordance with the ‘Code is Law’ policy.
Nevertheless, most of these problems exist purely because of how young smart contracts are as a technology. With such promise, the technology will surely be perfected over time. Undoubtedly, smart contracts are about to become the integral part of our society.
想象以太坊就是个大菜场，你和商贩不需要讨价还价，只需要自动执行的智能合约就行了。比如把猪肉30块一斤写在智能合约里，想买猪肉只需要付30块以太币（ETH）就能把猪肉买回家。
由于以太坊创始人Vitalik Buterin（V神）对以太坊的巨大影响，以太坊一直在理想主义与现实主义中反复寻找发展方向。目前仍然以实际应用为主（如ICO发币、Dapp去中心化app、DeFi去中心化金融）等等。而比特币由于创始人中本聪的神秘消失，越来越得到投机资本的青睐。现在越来越多的跨国公司，苹果、特斯拉等等都加入其中。就像画家死后画才值钱一样，中本聪的消失非但没成为比特币价格增长的阻碍，反倒给人以大局已定、坐等升值的安全感。
Non-fungible tokens (NFT) are digital assets that represent a wide range of unique tangible and intangible items, from collectible sports cards to virtual real estate and even digital sneakers.
One of the main benefits of owning a digital collectible versus a physical collectible like a Pokemon card or rare minted coin is that each NFT contains distinguishing information that makes it both distinct from any other NFT and easily verifiable. This makes the creation and circulation of fake collectibles pointless because each item can be traced back to the original issuer.
Unlike regular cryptocurrencies, NFTs cannot be directly exchanged with one another. This is because no two NFTs are identical – even those that exist on the same platform, game or in the same collection. Think of them as festival tickets. Each ticket contains specific information including the purchaser’s name, the date of the event and the venue. This data makes it impossible for festival tickets to be traded with one another.
The vast majority of NFT tokens were built using one of two Ethereum token standards (ERC-721 and ERC-1155) – blueprints created by Ethereum that enable software developers to easily deploy NFTs and ensure they’re compatible with the broader ecosystem, including exchanges and wallet services like MetaMask and MyEtherWallet. Eos, Neo and Tron have also released their own NFT token standards to encourage developers to build and host NFTs on their blockchain networks.Read more: Do You Know Where Your Digital Art Lives?
Other key characteristics of NFTs include:
NFTs have become hugely popular with crypto users and companies alike because of the way they revolutionized the gaming and collectibles space. Since November 2017, there has been a total of $174 million spent on NFTs.
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Thanks to the advent of blockchain technology, gamers and collectors can become the immutable owners of in-game items and other unique assets as well as make money from them. In some cases, players have the ability to create and monetize structures like casinos and theme parks in virtual worlds, such as The Sandbox and Decentraland. They can also sell individual digitals items they accrue during gameplay such as costumes, avatars and in-game currency on a secondary market.
For artists, being able to sell artwork in digital form directly to a global audience of buyers without using an auction house or gallery allows them to keep a significantly greater portion of the profits they make from sales. Royalties can also be programmed into digital artwork so that the creator receives a percentage of sale profits each time their artwork is sold to a new owner.
William Shatner, best known as Captain Kirk from “Star Trek,” ventured into digital collectibles in 2020 and issued 90,000 digital cards on the WAX blockchain showcasing various images of himself. Each card was initially sold for approximately $1 and now provides Shatner with passive royalty income every time one is resold.Read more: NFT art sales reached all-time high of $8.2M in December
Like all assets, supply and demand are the key market drivers for price. Due to the scarce nature of NFTs and the high demand for them from gamers, collectors and investors, people are often prepared to pay a lot of money for them.
Some NFTs also have the potential to make their owners a lot of money. For instance, one gamer on the Decentraland virtual land platform decided to purchase 64 lots and combine them into a single estate. Dubbed “The Secrets of Satoshis Tea Garden,” it sold for $80,000 purely because of its desirable location and road access. Another investor parted with $222,000 to purchase a segment of a digital Monaco racing track in the F1 Delta Time game. The NFT representing the piece of digital track allows the owner to receive 5% dividends from all races that take place on it, including entry ticket fees.
Dragon the CryptoKitty continues to be one of the most expensive NFTs in the space, valued at 600 ETH.
The one-of-a-kind “1-1-1” race car from F1 Delta Time sold for 415.9 ETH in May 2019.
Alien #2089 sold for 605 ETH in January 2021. This NFT is part of the CryptoPunk collection, the first NFTs ever created. Overall, there are 10,000 different CryptoPunks and only nine Alien CryptoPunks.
An NBA Topshot digital collectible card of basketball star LeBron James sold for $100,000.
An Axie named Angel from the NFT-based game Axie Infinity sold for 300 ETH.
一句话，Hold住！
韭菜搞比特币切记炒短线。“老子买股票，股市收盘了就不亏钱了。老子买比特币，妈的24小时亏钱”。普通人买比特币，最佳策略就是Hold住，实在Hold不住的，把交易所软件卸载了也行。
从 2013 年的 100 美元，到今天 2020 年 1 万美元，比特币在过去 7 年时间内已经涨了 100 倍了。持有比特币的人相信在未来十年内，比特币价格将继续猛涨（猛涨的理由千奇百怪，可以是“数字黄金”的故事、可以是“互联网货币”的故事，跟信佛一样），因此选择囤币然后在很长一段时间后再卖掉就是有利可图的。而且这种方法不需要像做短线交易那样频繁关注比特币短期的价格，尤其是对于想要分散投资（不想all in房市）的人来说，是更安心、也更省精力的做法。
挖矿就是“做题”， 矿工就是“做题家”。挖矿的过程就是比特币系统出一道数学题，看谁先做对。
比特币交易将验证交易的工作去中心化，靠用户彼此协助验证，而验证过程就是让计算机解出一连串复杂的密码学题目，解完题目、完成验证后，便能将交易双方的钱包地址、交易金额和时间等相关信息新增至新的「区块」中，这整个过程便称为「挖矿」，成功完成验证的「矿工」可获得一定数量的比特币作为奖励。
就像做题家内卷一样，解题难度会随着越来越多人投入挖矿而变难，矿工也需要用更强大的计算机才能成功解题，为了提高运算能力，矿工们会集结各自的计算机运算能力进行共同挖矿，再按照贡献程度进行拆分收益，因此个人矿工已越来越难和专业挖矿组织竞争。
组织聚集处就被称作「矿池」，其通常设在像中国等电费较低廉的国家，而目前全球主要矿池有58%来自中国，挖矿趋势伴随而来的便是能源消耗问题，也传出部分学者与科学家利用公有资源，使用运算效能极强的超级计算机进行挖矿。
By 知乎
DeFi是一个由众多金融服务机器人所组成的全新金融服务网络。
所有的 DeFi协议，本质上都是在提供⼀种⾦融服务，也就是说，是由⾦融服务机器人来提供⾦融服务，类⽐到传统世界⾥，就是⼀家银行给你提供借贷服务，或者⼀家理财公司帮你理财，⼜或者是
⼀家基金公司帮你做投资等等。这些⾦融机器器⼈其实就跟传统世界的⾦融服务公司是⼀样的，不同的是，这些机器器人是自动执⾏，⾃动操作，并且是完全去中⼼化运⾏，由代码组成。
所以，作为⼀个普通⽤户，我们玩DeFi，我们进入DeFi世界，就等同于来到了一个有很多机器人的房间。如果我们想使⽤某种金融服务，包括借贷、交易或者衍⽣品等等，就⾛到其中某⼀个机器⼈
的面前去使⽤它的⾦融服务，那这些机器⼈形成的市场就叫 DeFi。
具象化些，什么是金融服务机器⼈呢？
以Compound为例，Compound是提供抵押借贷的⾦融服务协议，我们称机器人小C。⼩C可以给⼩明提供抵押借贷服务。借贷⼈小明⼿上有⽐特币，假设1个比特币价值1万美元，并且小明认为比特币会涨到10万美元，但是⼩明现在缺钱，怎么办呢？⼩明可以不卖掉比特币，⽽是把⽐特币做抵押借贷，给到⼩C机器人，再获得贷款，可能是6000美元或者是5000美元。
5000美元或6000美元从哪里来呢？从⾦主小红，小红⼿手上有闲置资金。⼩C是机器器⼈，是完全透明公开，去中⼼化的。机器人⼩C跟⼩红说，你把钱放到我这，可以确保绝对安全。如果⼩明不愿意还钱，我就把他的⽐特币卖掉，让你把这笔钱拿回来。通过这样的方式，小红就放⼼且愿意把闲置资⾦给到Compound。
By 知乎
You may have heard of decentralized finance (DeFi). It’s the newest craze to enter the cryptocurrency
world, with billions of dollars having been invested in DeFi products in 2020 alone.
Increasingly, Bitcoin holders are getting involved in DeFi by “locking up” their coins in exchange for tokens that can be used on DeFi platforms.
DeFi products are tools built predominantly on Ethereum
that aim to revolutionize and replace the current methods of borrowing, lending and banking as seen with traditional finance.
The aim of DeFi is to make the world of finance available to all (or to anyone who has an Internet connection).
The majority of DeFi platforms are built on Ethereum. But there are a lot of people who own a lot of Bitcoin
who want to get involved too. So it is becoming increasingly easy for those with Bitcoin to be able to invest in DeFi platforms with their funds.
Bitcoin is the biggest cryptocurrency by market cap, so it makes sense for things to be moving in a direction that links the asset with DeFi products.
Bitcoin DeFi works by basically allowing Bitcoin—a currency on one blockchain—to run on Ethereum’s very different, separate blockchain.
How? This is where things get a little complex.
You can’t use Bitcoin directly on Ethereum platforms—as mentioned before, the blockchains are different. In order to do so, the Bitcoin needs to be converted into a currency that represents Bitcoin but is really an Ethereum-based token.
2) Wrapped Bitcoin (WBTC) is the first ERC20 token backed 1:1 to Bitcoin. It’s aiming to bring the representative and new use-cases of Bitcoin into Ethereum blockchain. pic.twitter.com/NtaKbZvsdm
— WBTC (@WrappedBTC) May 23, 2019
Then, the Bitcoin is essentially locked into a smart contract
, (a piece of code that performs instructions to replicate agreements) and can be used on the network. Think of it like a swap.
Why would someone want to put their Bitcoin in Ethereum smart contracts, you might ask, when they could just buy Ethereum tokens directly and get started from there?
One good reason is to make your Bitcoin work for you in the form of passive income. We all know that a lot of people hold onto their Bitcoin as a store of value—not for purchasing things online (as was originally intended) or remittance payments. What are DeFi loans?One of blockchain and cryptocurrency’s great promises is to take tools used by the financial industry and make them available to everyone everywhere. The catch-all term for this revolution in …LearnThe LandscapeMatt HusseySep 3, 2020
Besides, there are many other cryptocurrencies that serve that purpose now, some argue. So when Bitcoin is just sitting there as an investment in the hope that its value will one day skyrocket, why not use it to make money for you in the meantime?
One of the ways to generate passive income with Bitcoin is to utilize a DeFi platform to lend and earn interest with Bitcoin that would otherwise just be sitting around. It works like this: convert the Bitcoin into Ether or directly into Dai (a stablecoin, pegged to the US dollar) and put it in a platform where you could lend it out and receive loan back with interest.
One way of doing this would be to use the MakerDAO platform.
A relatively new concept, there are a handful of companies currently leading this space. They include Wrapped Bitcoin (WBTC), RenVM, and RSK.
Right now, more Bitcoin than ever before is being sent over to Ethereum; nearly $1 billion worth, as of September 2020. This is undoubtedly due to the rise of DeFi. As the scene has grown in popularity, so have the methods of making Bitcoin run on such platforms.
Companies in the space are reporting record amounts of Bitcoin being converted into ERC-20 tokens.
As long as DeFi is popular, we will continue to see new companies work in this space to provide quick, easy and cheap ways to help Bitcoin work on DeFi platforms.