Author: lisajohnsonam

Monero (XMR) is a cryptocurrency which focuses on being untraceable and private. Its design differs from Bitcoin’s in a few key ways, but it should be understood as a cryptocurrency similar to Bitcoin – it can be used to buy and sell things, and can be exchanged for other  coins or tokens.

So Monero XMR is a cryptocurrency focused on privacy and anonymity. Bitcoin is actually pseudonymous and BTC transactions are still traceable, but XMR transactions can be fully anonymized like physical cash. It is a fork of Bytecoin, the original privacy coin.

Of course, each physical dollar has a serial number on it that’s traced by FDIC-insured banks and governments. But it’s not necessary to see someone’s bank account balance to accept their dollar bill. In the same way, retailers only need to verify you have enough to cover your transaction when you use a debit or credit card.

Monero uses ring signature cryptography to reduce the amount of information used in cryptocurrency transactions. This gives the sender and receiver of XMR transactions the ability to verify the transaction in privacy.

Strong encryption, a streamlined blockchain, and infinite supply make Monero a strong privacy coin with a solid future ahead of it. Before diving into the nuts and bolts of the project, let’s look at the crypto market performance of the Monero XMR crypto coin.

XMR’s Crypto Market Performance

The peak price of XMR so far was $494.16, which occurred on January 6, 2018. As mentioned above, there’s no total supply cap, but over 16,500,000 XMR are in circulation.

Like BTC, XMR is a Proof of Work cryptocurrency. Unlike BTC, however, it uses a variation of the CryptoNote cryptocurrency mining algorithm, which making it more CPU-friendly. In fact, Monero continues updating its blockchain protocol to be ASIC resistant, much to the chagrin of ASIC rig manufacturers like Bitmain. It hard forked in both 2017 and 2018 in its war on ASICs.

Monero opposes ASIC mining because of its centralization of cryptocurrencies like Bitcoin and Ethereum, which are now moving toward Proof-of-Stake. It spent much of 2017 and 2018 continuously upgrading both ASIC resistance and privacy on the network. These are great signs of development support in a blockchain market filled with vaporware.

This caused a lot of Monero forks, including Monero Original (XMO), Monero 0 (ZMR), Monero Classic (XMC), and MoneroV (XMV).

Monero is traded on a variety of cryptocurrency markets, including Bithumb, Binance, HitBTC, Poloniex, Bitfinex, and CoinEx. It has a ton trading pairs, including BTC, BCH, USDT, LTC, ETH, EOS, DASH, and even fiat currencies like USD and EUR. Over $25 million worth of XMR is traded on a daily basis.

The Monero community built wallets for pretty much every OS, and a hardware XMR wallet is on the way. In addition, third-party wallets like Cake Wallet, Monerujo, My Monero, and Ledger’s hardware wallets support XMR.

Behind the Veil of Anonymous

Anonymity online is a hot-button issue that’s important for everyone. Every time you log in to your Samsung device using Google’s OS to connect to AT&T’s network and browse Amazon’s app, a lot of hands are touching, monitoring, and even selling your data and habits. Tech-savvy people use VPNs, proxies, and TOR networks to avoid being traced.

However, financial transactions and other personal information were used to track people centuries before we walked around with the internet in our pockets.

Using XMR for dark-web transactions, you have the best chance at anonymous online transactions…at least that’s what they say.

Monero aggressively defends its platform’s privacy, pointing out a CryptoNote bug that affects privacy coins like Bytecoin. But privacy and anonymity online are never guaranteed, even with Monero’s dedication.

Monero still uses a similar two-key authentication method for transactions on other blockchains. It just adds an extra step. Your public key is used by the sender to generate a random one-time key, and the receiver uses a private key to receive. Brute-forcing such a system would be difficult, even with quantum computing, but no matter how much you encrypt an individual transaction, metadata holds answers.

This is where ring signatures come in to make things even more difficult. Essentially every output also has multiple false outputs to trick the system. Picture the most complicated bank vault you ever saw in a major Hollywood movie, multiply by ten, and this is what Monero promises.

Tor traffic has long been monitored by government watchdogs like the NSA using the Navy’s powerful networking tools. And even reducing transactions to minimal data hasn’t stopped researchers from reportedly using big-data analytics to trace over 80 percent of XMR transactions on the Monero blockchain.

While the actual transaction itself is being veiled, all the contextual information around it can help pinpoint transactions. In addition, if your private key is compromised, someone could trace all your individual transactions, so it’s vital you keep your private Monero key secure.

Still, the anonymous core development team led by Riccardo “fluffypony” Spagni and David Latapie built a lean, secure, and efficient blockchain-based cryptocurrency. He’s also quick to point out shortcomings in other crypto projects like BAT.

Disparaging the security of a system like Monero isn’t exactly fair, as it’s still more secure than most blockchains and at least as secure as systems used by Bank of America, Visa, Wall Street, and other financial institutions. It’s using government-grade encryption, and that’s good enough for now.

Privacy coins are in the crosshairs of regulators, and even though transactions can be secure on their blockchains, most market trades are required to be logged.

Monero Summary

Monero XMR is a privacy coin that forked from Bytecoin to become one of the highest ranked cryptocurrencies by market cap. It’s widely used in darknet marketplaces instead of Bitcoin because it promises anonymity instead of pseudonymity. Monero’s success depends on these key factors:

• Monero XMR uses ring signatures to mask randomly-generated authentication keys and keep transactions both secure and slimmed down to only pertinent information.
• Mining XMR can still be done on home PCs. In fact, the Monero community aggressively upgrades its network to remain ASIC resistant.
• Monero has a lot of trading pairs, making it easy to get into and out of. This accessibility will help it maintain high trading volumes for years to come.

So long as Monero and privacy coins like it don’t come under regulatory fire, XMR is a solid cryptocurrency that’s seen a lot of use since its inception. An active development team and community make this privacy coin one to watch for years to come.

门罗币的起源要追溯到2014年，当时有一位极客为了改善比特币的匿名性，发布了一个CryptoNote协议，不久之后，基于这个协议诞生了首个匿名币——字节币（Bytecoin）。

与比特币相比，字节币的匿名性更好，更注重隐私保护，因此，一经推出，也受到不少极客的热捧，几周后，字节币的GPU矿机诞生。

但很快有些人发现，开发者竟然预挖了82%的代币！这在崇尚去中心化的数字货币世界，无疑会遭到许多人抵制的。

于是，社区直接对字节币进行硬分叉，2014年4月18日这天，门罗币正式诞生，英文名称为Monero，简称 XMR 。

与比特币类似，门罗币同样采用了工作量证明机制 ( POW )，但没有采用 SHA-256算法，而是 CryptoNight 算法。

在比特币中，由于区块链账本的公开及可追溯性，任何一个人都可以通过比特币区块链浏览器的公开信息，顺藤摸瓜查出来所有和它有往来关系的比特币账户，因此，比特币的匿名性并非是无懈可击的。

门罗币则采用了环签名和混淆地址的方式来保证匿名性。其交易不仅隐藏交易双方地址，而且还可以隐藏交易金额，默认情况下交易细节完全不可见，隐私性极强。所谓环签名，就是当一笔交易发生后，系统自动生成几组同额度当交易，通过这种“真假混合”的方式，让你根本查不出来到底这个币去了哪个地址。

此外，门罗币没有上限。

不同于比特币有总量上限（2100 万），门罗币会一直通胀下去，但每区块的挖矿奖励会逐渐降低直至 0.6 门罗币（预计发生在 2022 年下半年，当前的每区块挖矿奖励约 2.5 XMR）。

比特币平均每 10 分钟一个区块，门罗币平均每 2 分钟一个区块，区块没有固定的大小限制。为了防止矿工通过超大区块堵塞系统，门罗币设置了一个挖矿奖励惩罚机制（Reward Penalty）：

每一个新生成的区块，如果超过了 300000Bytes，而且还超过了最新的 10 万个区块大小的中位数（去年 3 月份分叉之前，是最新的 100 个区块大小的中位数），就会受到区块奖励减少的惩罚。

门罗币隐身的秘诀

门罗币运用了三大技术，分别是：环签名、混淆地址、环机密技术。

在交易环节，主要涉及［发送方］［接收方］［交易额度］三个数据，门罗币对应的三项技术，正是从这三个角度着手。

环签名 – 发送方，不可追踪性

打个比方，大家联名上书提意见的时候，怎样让外界难以猜测发起人是谁？上书人的名字可以写成一个环形，环中各个名字的地位看上去彼此相等，因此难以猜测发起人是谁。假设，A发送门罗币给 B，设定混淆交易数量为5。网络在转账时会自动生成5笔转账交易，除了A发送给B的这笔，另外的4笔都是用来瞒骗外界观测者的“诱骗交易”，这样达到隐匿发送方的目的。

混淆地址 – 接收方，不可关联性

混淆地址是为了打破输入输出地址之间的关联，以此隐匿转账的来去关系。每当发送者要发起一笔转账的时候，这笔资金不会直接打到接收方的地址，而是打到一个系统临时生成的地址。例如，A向B转账时，A作为发送者用B的公钥私钥加上一些随机数，生成一个独一无二的、一次性的地址，系统给这个临时地址转账。A和B自己都能看到这个临时地址，但都不知道地址里的钱属于谁。

那么B怎么知道有人给自己转账，怎么收到这笔钱呢？B的钱包会用私钥进行搜索功能，查看区块链上的临时地址是否有属于自己的钱。当B的私钥（仅有接收方B自己的私钥能够）识别出自己有权认领的临时地址，就能使用这笔钱。

环机密 – 交易金额的隐匿

在A向B转账时，在 RingCT 的交易中, A 不会直接公开给网络转账的金额，而是提供一个数字rct，作为交易金额输出。rct= 随机数 + 真正的交易金额。随机数是用来为真实金额遮盖的，由钱包自动产生。网络可使用这个rct值去验证交易输入是否等于交易输出的金额，以确认没有额外的 Monero 被伪造产生。 然而，对于其他人而言，无从得知实际交易金额。

对抗矿霸

门罗币天生为了不公平而战斗。

2018年，比特大陆推出了门罗币ASIC矿机，门罗币开发团队立马表示抵制，并不惜用硬分叉修改算法，以防止ASIC大范围抢占矿机生态。

为什么抵制ASIC？ASIC矿机的算力非常强大，如果大家都买ASIC，就容易被供应商控制，或者比特大陆自己成本价用ASIC挖，那又回到算力独大导致所谓中心化的问题了。

门罗币社区的激烈反应令比特大陆始料未及，如果新版的算法不支持ASIC矿机，那么ASIC矿机将成为一堆烂铁。

作为曾经叱咤加密货币市场的王者，比特大陆自然不能坐视不理。

2017年曾推动比特币分叉，并产生比特现金，这次故伎重演。

比特大陆马上招募技术团队，对门罗币进行分叉，于是门罗经典(monero-classic)诞生，门罗经典支持ASIC矿机，比特大陆一再宣称，门罗经典才是正统。

但就在分叉后不久，门罗经典由于缺乏社区支撑，最终江河日下，一蹶不振。

相反，门罗币就像一个战士，越战越勇，目前在市值20亿美元，排名 14 。

资料来源：https://www.bixiaobao.com/cn/coinlist/monero

在门罗币的官网上可以看到，门罗币目前一共有 7 名核心开发者，此外，自门罗币创始以来已经超过500名开发者为其贡献代码，从这点来看，门罗币社区确实十分强大。

为了对抗矿霸与黑客，门罗币平均每六个月就升级一次算法，门罗币最初使用的是CryptoNight算法，后来在对抗ASIC矿机中升级了RandomX算法，在对抗黑客的过程中加入了防弹协议（bulletproofs）。

门罗币的监管风险

门罗币的匿名性既是其最大的优势，也是其最大的弱点。隐匿有价值，但它也可以使非法活动不受惩罚，加大了监管的难度。

2018年3月，Coincheck称将下架 XMR、DASH 和 ZEC 三大匿名加密货币。另外许多韩国与日本的交易所也相继下架诸如 XMR、ZEC、DASH 等等这些具有匿踪匿名传输与交易功能的货币，据推测，这些举措和政府监管有关。

除了监管问题外，门罗币的隐私保护措施也并没有那么强大。WIRED杂志早些时候发表了一篇关于门罗币隐私弱点的文章，来自不同大学的研究人员指出了门罗币的交易混合算法中的缺陷，该缺陷破坏了其无法追踪的特性。针对这些问题， 门罗币的开发人员对门罗币进行了定期和持续的改进。不过， 隐私不是一蹴而就的，会是一场持久的战斗。

不可否认，门罗币在不牺牲去中心化的情况下为加密货币引入了隐私，使用创新技术来确保交易不可关联，无法追踪，并且发送的金额被隐藏起来，还是值得肯定的。目前门罗币的开发人员也在针对存在的扩展性、被黑客攻击以及数据滥用等问题进行改进，但是政府的监管还是不能忽视的不确定因素。

参考资料：

1.门罗币价格：https://www.bixiaobao.com/cn/coinlist/monero

2.维基百科：门罗币

3.门罗币官网：www.getmonero.org

4.市后诸葛《门罗币：你有矿机你有钱，我换算法还不行吗？》

5.白话区块链《门罗币是什么》

By 链得得-币小宝

Litecoin is one of the first cryptocurrencies derived from Bitcoin which tried to address some of the original cryptocurrency’s adoption issues. Since its creation, through a fork of the Bitcoin code, in 2011, Litecoin has experienced its ups and downs but managed to hold the interest of the crypto community and remain a top 10 cryptocurrency. Even so, it faces stiff competition from other protocols such as Bitcoin Cash and Bitcoin SV in its positioning as a viable protocol for mass on-chain transactions.
 

Beginnings

Litecoin (LTC) is a peer-to-peer digital currency based on a decentralized, open source blockchain network. It was created in 2011 by the MIT graduate and former Google employee Charlie Lee.

Lee designed Litecoin based on the Bitcoin code and protocol, with some modifications that he believed addressed certain barriers to its wider adoption. Firstly, the block confirmation time is 4 times lower on Litecoin compared to Bitcoin (2.5 min vs. 10 min) which allows Litecoin to confirm transactions much faster. Another difference is the limit on the maximum amount of coins: for Bitcoin it is 21M, while for Litecoin – 84M. Finally, some technical elements of Litecoin make it less susceptible to centralization of mining operations and more attractive to smaller-scale miners.

Litecoin was one of the first altcoins to spring from the Bitcoin protocol. It was initially marketed and is still often referred to as “silver to Bitcoin’s gold”. Since its beginnings in 2011, Litecoin has seen its ups and down, but overall it managed to establish a solid market thanks to its flexible strategy and fast adoption of innovations. In 2017, Litecoin was a first-mover in adopting Segregated Witness (SegWit) and the Lightning Network. Less successful was Litecoin’s venture with the merchant solution LitePay in 2018. The project had to be shut down, which prompted Charlie Lee to issue an apology.

The development of the Litecoin project is overseen by a non-profit Singapore-based Litecoin Foundation, with Charlie Lee as a managing director. Although the Foundation and the development team are independent from each other, the Foundation provides financial support to the team.
 

Uses

Litecoin functionality is overall quite similar to Bitcoin, i.e. it is meant to be a digital currency which is free from any centralized influence. The LTC philosophy is formulated by the Litecoin Foundation on their website, “We Believe That When It Comes To Your Money, You Deserve 100%”. The statement generally refers to the promises common to most cryptocurrencies: constant availability and absolute control of the funds by the owners, and the accessibility to everyone.

LTC can be purchased on any major crypto exchange, and stored in digital wallets, specialized hardware, or crypto custody providers. Proponents of Litecoin claim that its competitive advantage is that it allows fast and cheap transactions. Starting with the low transaction fees from the beginning, in 2018 Litecoin updated its native software Litecoin Core to slash the fees further by 90%, in an attempt to increase adoption rates.

Speed and low fees should make it attractive for individuals to use Litecoin for peer-to-peer transfers and digital purchases, and for businesses – as a payment system. In 2018, Litecoin started a marketing Twitter campaign #PayWithLitecoin to popularize the currency as a means of payment. However, the list of businesses accepting it remains limited.

As most crypto assets, LTC experienced some serious price volatility since it started trading. The price has reached its peak above $300 in the end of 2017. During 2020, LTC was mostly trailing just below the $50 mark. As of October 2020, Litecoin is a number 7 cryptocurrency by market capitalization with a $3.6B market cap (for comparison, Bitcoin’s market cap is $256B).
 

Outlook

In 2020, one of the most interesting trends in Litecoin development is the work on MimbleWimble.. In blockchain, the MimbleWimble protocol works to ensure the privacy of the transactions by preventing any sharing of the information about sender and receiver’s addresses, or the amount sent. Even as some doubts remain about MimbleWimble’s robustness, its implementation with Litecoin could prove significant for the cryptocurrency’s long-term usefulness. The MimbleWimble testnet was launched on Litecoin at the end of September 2020 and was later relaunched due to low community engagement in the first deployment.

Another interesting development that could influence the future of Litecoin is its venture into the gaming industry. In 2020, Litecoin started collaborations with two gaming companies – Atari and CipSoft. Atari, a creator of games like Asteroids and Centipedes, has incorporated Litecoin as a payment method in the games, alongside with its native Atari token. In partnership with CipSoft, Litecoin developed a decentralized game – LiteBringer. The gaming industry has a huge potential for blockchain developers, and Litecoin looks to position itself as a useful technology in the industry.

On the whole, Litecoin’s development and usage trails that of other top ten cryptocurrencies as the industry grows beyond a simple focus on payments and looks towards the wider horizons of Web 3.0.

By BitcoinSuisse

狗狗币的崛起正应了李笑来说的“傻逼的共识也是共识”。其实这个世界的真相是“傻逼的共识才是共识”。

狗狗币的创始人一个是营销狗Jackson Palmer，一个是码农Billy Markus，因为看不顺眼比特币被少数人垄断，这两人就做了一个发行量高达1280亿枚的狗狗币，让2100万枚的比特币在它眼里就是个小case。

狗狗币在全世界的走红有以下几点原因：

第一，好币种,要有好作者,很多山寨币，作者都不敢公开出来。可以说跟本找不到作者，或是作者本人，也只是想打一炮就走人，像国内的一些山寨币，偷挖现象非常严重。创始人Jackson Palmer和Billy Markus一直在认真推广狗狗币，在开创之初就把狗狗币定位为电子货币来发行。

第二，好币种，必需有一个好的文化背景，在小费文化的大背景下，狗狗币作为电子货币，诞生于2013年12月12日，比特币现在的价格比较高，所以更便宜的Dogecoin受到欢迎。其上线仅一周的时间，便成为第二大的小费货币。他们希望脸书能够接受Dogecoin，现在，脸书已经正式接受狗狗币做为打赏货币，这样你的朋友不仅可以点赞，还可以顺便给你点小费。Palmer也提到，Dogecoin并不像比特币那样，人们并不是为了投机才参与其中，这是一种表达分享和感恩的方式。

第三，好币种，要有比较大的成交量，我在C网上发现，狗狗币的成交量，自从上线以来，一直都是排在第一位。超过其它所有山寨币包括莱特币的成交量，只有成交量大，流通性好。才有可能成为一种货币。而且，狗狗币在所有币挖完后，每年，还有50亿狗狗币的币产出，1年后通涨是5%。20年后通涨是2.5%这样，有一定的通胀。才更符合人类货币的规律。在14年7月中旬减半以后，狗狗币的实际通涨比BTC和LTC都小。适当的通涨会稳定货币价值，不会造成通货紧缩。因为，货币在流通过程中，有可能出现其它原因，如自然丢失等，造成丢币的情况。

第四，好的币种，要有相应的应用在支持，目前来说，所有的山寨币，只有狗狗币，和比特币一样，有自己电脑钱包和手机的安卓钱包，狗狗币也有推出U盘钱包，狗狗币，狗狗币已经推出ATM机。,狗狗币的矿机也已经推出,这样的话,从挖矿交易平台和ATM机,一条完整的产业链就会出现.一个完整的产业链，才会吸引到更多的大资金来关注。

第五，狗狗币，自从推出以来，一直有大的新闻媒体在关注，并支持，从推出到现在，才用了不到3个月的时间，就在算力上已经稳定在第三，交易量，一直排在全球前三名，钱包下载量也是全球第一，狗币人气在Twitter.facebook关注人数分别排名第1和第2 ,国内与狗狗币相关的QQ群个数，百度贴吧，新闻曝光度等综合 排名第2,狗狗币人气也远远超过了所有的山寨币。比特币,莱特币,狗狗币形成三币天下的格局.BTC用来储备或大额消费，LTC和狗狗币用来流通或小额消费。

第六，狗狗币，在国内有成立中国狗狗币协会，为推动狗狗币的发展发挥巨大的力量.中国狗狗币协会官网www.chinadoge.cn。有中文论坛论坛http://www.dogebbs.com，狗狗币资讯网http://mydoge.org/。目前国内比较活跃的QQ群有：340816166 ，101375418, 341817239。而其它的山寨币，大部分只有炒作，没有应用支撑，交流的地方都没有。另外，狗狗币做为和互联网游戏相结合的电子货币，以狗狗币做为游戏币的游戏已经正式推出。狗狗币和游戏相结合，会成为是狗狗币的另一个主要应用。

详情请戳江恩-巴比特

The cryptocurrency Dogecoin was created as a joke but eventually found a purpose as a more friendly, approachable alternative to Bitcoin. The Dogecoin community has catapulted DOGE to cult status. Today it is often used as an entry-point into the crypto world. Dogecoin is a cryptocurrency based on Luckycoin (which is, in turn, based on Litecoin). Dogecoin was originally designed to be a more approachable alternative to Bitcoin, Litecoin, and other cryptocurrencies. As such, there aren’t any groundbreaking features that set Dogecoin apart from the pack. The cryptocurrency hasn’t seen any major updates since 2015 (although it is able to benefit from improvements to the Litecoin code). The true value of Dogecoin lies in the strong and vibrant community that sprung up around it.

Six Interesting Facts About Dogecoin

• Dogecoin was originally founded as the result of a joke made by Jackson Palmer in November 2013. When he was contacted by programmer Billy Markus, they decided to turn Dogecoin into a reality.
• Dogecoin was designed to be a friendly, more approachable form of cryptocurrency that could reach users put off by the cold complexity of Bitcoin. Even its name is taken from a popular Internet meme.
• Dogecoin has one of the largest and most active communities in the cryptocurrency world. This community has come together to fund a number of charitable efforts and other projects. They even managed to sponsor a NASCAR.
• One of the most common uses for Dogecoin today is as a tipping service. Users will tip other users for posts or contributions that they believe deserve recognition. It’s similar to a “like” but with more impact.
• There have been no technical updates or developments since 2015 when Jackson Palmer left the project by declaring that he was going on an “extended leave of absence”.
• In 2021 Dogecoin saw a major price surge thanks to an influx of users chasing GME style highs. This run was given a further boost when Elon Musk began tweeting about Dogecoin, calling it the “cryptocurrency of the people”.

What’s Different About Dogecoin? The main thing that separates Dogecoin from most other cryptocurrencies is that it is an inflationary, rather than deflationary, cryptocurrency.

When a cryptocurrency, like Dogecoin, is inflationary, it means that there is no maximum limit to the number of coins in circulation. Bitcoin and many other cryptocurrencies are designed with a hard supply cap of coins. The potential problem with this is that once the cap is reached it may no longer be profitable for miners to continue to sustain the system. This would either lead to unacceptably high fees in order to encourage miners or very long transaction times as there would be no incentive to process network transactions.

Miners Are Rewarded With Dogecoin

Dogecoin’s creator sought to solve this problem by ensuring that miners would always be rewarded with new Dogecoin and so there would always be an incentive to mine more coins. An inflation-based approach was also designed to replace lost coins and keep Dogecoin at a stable 100 billion coins.

More details on Commedity.com

Kevin Voigt

The value of Bitcoin broke all records in February 2021.

The spot price to buy a bitcoin — the world’s first and most popular digital currency — briefly rose above $58,000 on February 21. (For context, the cryptocurrency’s all-time low is from 2013, when it was priced at $67.81.) With such a meteoric rise, many are wondering: What, exactly, is Bitcoin, and where does it get its value? Years from now, will we talk about the Bitcoin boom and bust periods as we do about the Gold Rush? Or, will it become a staple in a diversified investment portfolio and a common way to buy a pizza?

For the most part, the jury’s still out. But the past 10 years have given us a better indication of the role Bitcoin might play in the portfolios of retail investors and large institutions alike.

Definition: What is Bitcoin?

Bitcoin was launched in 2009 and is regarded as the first cryptocurrency. It’s a decentralized form of digital cash that eliminates the need for traditional intermediaries like banks and governments to make financial transactions. Still feeling a little confused? Don’t worry, that’s normal.

Fiat money (like the U.S. dollars in your bank account) is backed and regulated by the government that issues it. Bitcoin, on the other hand, is powered through a combination of peer-to-peer technology — a network of individuals, much like the volunteer editors who create Wikipedia — and software-driven cryptography, the science of passing secret information that can only be read by the sender and receiver. This creates a currency backed by code rather than items of physical value, like gold or silver, or by trust in central authorities like the U.S. dollar or Japanese yen.

“What is needed is an electronic payment system based on cryptographic proof instead of trust, allowing any two willing parties to transact directly with each other without the need for a trusted third party,” wrote Satoshi Nakamoto —  the pseudonym of the mysterious Bitcoin creator, who remains unknown — in a white paper introducing the open-source technology. It’s come a long way since then, now accepted as payment by AT&T, the Dallas Mavericks and Wikipedia, among others.

» Ready to buy? See NerdWallet-reviewed brokerages that offer Bitcoin.

How does Bitcoin work?

Each bitcoin (trading symbol “BTC,” though “XBT” is also used) is a computer file stored in a digital wallet on a computer or smartphone. To understand how the cryptocurrency works, it helps to understand these terms and a little context:

• Blockchain: Bitcoin is powered by open-source code known as blockchain, which creates a shared public ledger. Each transaction is a “block” that is “chained” to the code, creating a permanent record of each transaction. Blockchain technology is at the heart of more than 6,000 cryptocurrencies that have followed in Bitcoin’s wake.
• Private and public keys: A bitcoin wallet contains a public key and a private key, which work together to allow the owner to initiate and digitally sign transactions, providing proof of authorization.
• Bitcoin miners: Miners — or members of the peer-to-peer platform — then independently confirm the transaction using high-speed computers, typically within 10 to 20 minutes. Miners are paid in bitcoin for their efforts.

» Learn more: What is cryptocurrency? 

How does Bitcoin make money?

Bitcoin value follows the law of supply and demand — and because demand waxes and wanes, there’s a lot of volatility in the cryptocurrency’s price.

Besides mining bitcoin, which requires technical expertise and an investment in high-performance computers, most people purchase bitcoins as a form of currency speculation — betting that the U.S. dollar value of one bitcoin will be higher in the future than it is today. But that’s difficult to predict.

Storing your bitcoins: Hot wallets vs. cold wallets

Bitcoins can be stored in two kinds of digital wallets:

• Hot wallet: Digital currency is stored in the cloud on a trusted exchange or provider, and accessed through a computer browser, desktop or smartphone app.
• Cold wallet: An encrypted portable device much like a thumb drive that allows you to download and carry your bitcoins.

Basically, a hot wallet is connected to the internet; a cold wallet is not. But you need a hot wallet to download bitcoins into a portable cold wallet.

Buying Bitcoin: The pros and cons

With a speculative asset class like bitcoin, it’s better to start with why you should be wary:

Bitcoin: The cons

• Price volatility. The 2017 spike in Bitcoin’s price was driven by speculators rushing into the bitcoin market, as NerdWallet staff writers discussed at the time. The recent gains are good news if you bought Bitcoin in December 2018; those who bought in 2017 when Bitcoin’s price was racing toward $20,000 had to wait until December 2020 to recover their losses.
• Hacking concerns. While backers say the blockchain technology behind bitcoin is even more secure than traditional electronic money transfers, bitcoin hot wallets have been an attractive target for hackers. There have been a number of high-profile hacks, such as the news in May 2019 that more than $40 million in bitcoin was stolen from several high-net-worth accounts on cryptocurrency exchange Binance (the company covered the losses).
• Limited (but growing) use. In May 2019, telecommunications giant AT&T joined companies such as Overstock.com, Microsoft and Dish Network in accepting bitcoin payments. But these companies are the exception, not the rule.
• Not protected by SIPC. The Securities Investor Protection Corporation insures investors up to $500,000 if a brokerage fails or funds are stolen, but that insurance doesn’t cover cryptocurrency.

Bitcoin: The pros

• Private, secure transactions anytime — with fewer potential fees. Once you own bitcoins, you can transfer them anytime, anywhere, reducing the time and potential expense of any transaction. Transactions don’t contain personal information like a name or credit card number, which eliminates the risk of consumer information being stolen for fraudulent purchases or identity theft. (Keep in mind, though, that to purchase bitcoins on an exchange, generally you’ll first need to link your bank account.)
• The potential for big growth. Some investors who buy and hold the currency are betting that once Bitcoin matures, greater trust and more widespread use will follow, and therefore Bitcoin’s value will grow.
• The ability to avoid traditional banks or government intermediaries. After the financial crisis and the Great Recession, some investors are eager to embrace an alternative, decentralized currency — one that is essentially outside the control of regular banks, governing authorities or other third parties. (However, to buy Bitcoin on an exchange with U.S. dollars, you’ll likely need to link your bank account.)

Where can I buy Bitcoin?

There are four ways to get bitcoins:

• Cryptocurrency exchanges. There are a number of exchanges in the U.S. and abroad. Coinbase is the largest cryptocurrency exchange in the U.S., trading more than 30 cryptocurrencies.

» Learn more: Read our Coinbase review

• Investment brokerages. Robinhood was the first mainstream investment broker to offer Bitcoin and other cryptocurrencies (Robinhood Crypto is available in most, but not all, U.S. states). Tradestation, eToro and Sofi Active Investing also offering cryptocurrency trading in most U.S. states.

• Bitcoin ATMs. There are more than 7,000 bitcoin ATMs in the U.S. (search Coin ATM Radar to find one near you).
• Peer-to-peer purchases. True to its original spirit, you can buy bitcoins directly from other bitcoin owners through peer-to-peer tools like Bisq, Bitquick and LocalBitcoins.com.
• Bitcoin mining. You can earn bitcoins through mining, but the technical expertise required and computer cost puts this option out of reach for most.

Should you buy Bitcoin?

Bitcoin is an incredibly speculative and volatile buy. It’s worth remembering that stock trading can give you a similar thrill — and picking stocks of established companies is generally less risky than investing in Bitcoin. (A good rule of thumb is to devote less than 10% of your overall portfolio to individual stocks or speculative assets like Bitcoin.)

» Read our top picks for best online stock brokers

What online brokers offer Bitcoin?

Of the online brokerages and cryptocurrency exchanges that NerdWallet reviews, the following currently offer Bitcoin.

	Available for:	Learn more
Coinbase	Access to buy and sell more than 30 cryptocurrencies.	Read review
eToro	Trading platform with access to 15 cryptocurrencies.	Read review
Robinhood	Seven cryptocurrencies including Bitcoin, Bitcoin Cash and Ethereum.	Read review
SoFi Active Investing	Offers three cryptocurrencies for trading: Bitcoin, Ethereum and Litecoin.	Read review
TradeStation	Offers trading for five cryptocurrencies, including Bitcoin, Bitcoin Cash and Ethereum.	Read review
Webull	Offers four cryptocurrencies for trading: Bitcoin, Bitcoin Cash, Ethereum and Litecoin.	Read review

* These providers are NerdWallet advertising partners.

Disclosure: The author held no positions in the aforementioned securities at the time of publication.

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.

How do smart contracts work

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.

Interdependence

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.

Objects of smart contracts

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.

Environment

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.

Smart contracts give you:

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

Who created and who uses them

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

Examples of using smart contracts

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.

Cons

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.

By CoinTelegraph

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。