[SalesForce]Block Chain Basic3

下面的文章翻译自SalesForce的learing Material

https://trailhead.salesforce.com/content/learn/modules/blockchain-basics/blockchain-fundamentals

Learn Blockchain Fundamentals

Learn About the Types of Blockchain Networks

Learning Objectives

After completing this unit, you’ll be able to:

Identify the differences between public and private blockchain networks.
识别公有的和私有的区块链网络
Identify 3 things that separate blockchain designed for business from other networks.
3点用以将业务专用区块链与其他网络区分开。

Public vs. Private, Permissioned vs. Permissionless
公有与私有，许可与无许可

There are several flavors of blockchain that have emerged in recent years. Public or Private typically refer to who can see the data. Permissioned and Permissionless typically refer to who can join the network and add blocks to the blockchain.
近年来出现了几种种类的区块链。公有与私有通常是指谁可以看到数据。 许可和无许可通常是指谁可以加入网络并向区块链添加块。

Public Blockchain

The biggest difference between public and private blockchains is related to who is allowed to view the ledger. A public blockchain network is completely open for members of the public. Bitcoin was the first attempt to create a public blockchain network—anyone can view entries including who sent Bitcoin to whom and in what amount.
公有和私有区块链之间最大的区别在于谁被允许查看账本。 公共区块链网络对公众完全开放。 比特币是第一个尝试创建公共区块链网络的-任何人都可以查看条目，包括谁向谁发送了比特币以及发送给谁的金额。

Private Blockchain

Ledgers in a private blockchain are not visible to the public. In fact the existence of the network itself may be hidden. Viewing data on a private blockchain requires that users know about the network, have access to the network, and also typically requires that users have received the encryption keys necessary to view the data.
私人区块链中的分类帐对公众不可见。 实际上，网络本身的存在可能是隐藏的。 在私有区块链上查看数据需要用户了解网络，有权访问网络，并且通常还要求用户已收到查看数据所需的加密密钥。

These permissions control who is allowed to participate and may limit which transactions they are allowed to view and post.
这些权限控制着允许谁参与，并且可以限制他们被允许查看和发布的交易。

Access control in a private blockchain can vary:
在私有区块链中,权限控制可以很不一样

• Existing participants decide who joins既存的参与者来决定谁可以加入
• A regulatory authority issues licenses for participation监管机构颁发参与许可证
• Or a consortium makes the decision由财团联盟做出决定

Permissioned Blockchain
由许可区块链

Permissioned blockchain is the most important type of blockchain for businesses. In order to participate in a permissioned blockchain, users need to be invited. This step helps prevent anonymous participants.
许可区块链是商业中最重要的区块链类型。 要参与到许可的区块链来，用户需要被邀请。 这有助于防止匿名参与者的出现。

For legitimate business use of blockchain, anti-money laundering laws require that businesses know whom they are doing business with. A permissioned blockchain supports this by design. The Linux Foundation’s Hyperledger Fabric is an example of a permissioned blockchain. It has been designed from the ground up to cater to enterprise needs. It allows users to build either a public or private, permissioned blockchain network.
为了合法地使用区块链，反洗钱法律要求企业知道他们正在与谁开展业务。 有许可区块链可以通过设计来支持这一点。 Linux Foundation的Hyperledger Fabric是许可的区块链的一个例子。 它是专为满足企业需求而设计的。 它允许用户构建公共或私有的，有许可的区块链网络。

Permissionless Blockchain
无许可区块链

Permissionless blockchains allow anyone to join and update the network. This can be a strength or a weakness. Allowing anyone to join typically means there are no identity requirements, so users often attempt to be anonymous using pseudonyms. Bitcoin is an example of a permissionless public blockchain. In order to make an update to the Bitcoin ledger, miners have to perform resource intensive computations to earn the right to be the one to designate the next valid block.
无许可区块链允许任何人加入和更新网络。 这可能是优点或缺点。 允许任何人加入通常意味着没有身份要求，因此用户经常尝试使用化名匿名。 比特币是未经许可的公共区块链的一个例子。 为了更新比特币分类账，矿工必须执行资源密集型计算，才能获得指定下一个有效区块的权利。

Note

• Permissioned blockchains do not need miners like a bitcoin blockchain network does. They are more efficient at adding blocks.
  有许可区块链不需要像比特币区块链网络那样的矿工。 它们在添加块方面效率更高。

Blockchain for Business

There are three main things that separate blockchain designed for business from other networks.
把为商业设计的区块链与其他网络区分开来的,有三点。

• Assets over Cryptocurrency . Blockchain can be used for more than just cryptocurrency. Physical assets such as cars, real estate, and food, as well as other things such as bonds, private equity, and stock are all fair game.
  加密货币资产。 区块链不仅可以用于加密货币。 汽车，房地产和食品等有形资产，以及债券，私募股权和股票等其他资产，都是可以的。

• Identity over Anonymity. Businesses have customer and anti-money laundering rules that require them to know exactly whom they’re dealing with. Participants in business networks usually require the polar opposite of anonymity—privacy.
  匿名身份。 企业拥有客户和要求他们确切了解与谁打交道反洗钱规则。 商业网络中的参与者通常需要隐私--这与匿名性完全相反。

• Selective Endorsement over Proof of Work. Consensus in a blockchain for business is not normally achieved through mining, but more often through a process called selective endorsement. If you transfer money to a third party, then your bank, the recipient’s bank, and possibly a payments provider would verify the transaction. Selective endorsement is about being able to control exactly who verifies transactions.
  对工作证明的选择性认证。 商业区块链中的共识通常不是通过挖掘来实现的，而是通常通过称为选择性认证的过程来实现。 如果您将钱转移给第三方，则您的银行，收款人的银行以及可能的付款提供商会验证交易。 选择性认证是指能够准确控制谁验证交易。