BlockchainPrivacy(区块链隐私）

Privacy Protected vs. Privacy Non-protected Transactions

About Blockchain transaction

You might have heard of blockchain, and one of the features of the general blockchains is traceability, i.e. you can track all the historical transactions, by senders, recipients and amount. Look at the top half of the above diagram, for example, Alice sends 1 bitcoin to Bob, then on the bitcoin blockchain you will see the transaction like the following:

In this transaction, so we know 173XurTkp5yBrUfg6ng2kaEk9pm4qxzu5q transferred 0.00101883BTC to 12iVTz5rj1TpxXvaWrWFAxNwGKiXznYvsU. Even though we don&＃8217;t know who the sender and recipient are, if the associations could be established by other means, then all that person&＃8217;s past and future transactions will be exposed to the open public to explore.

To address the blockchain privacy issue, some technologies have been developed to enable the Blockchian Anonymity. For example, look at the bottom half the above diagram, there are 4 points where the privacy can be protected:

Point 1: Stealth Address to protect the recipient&＃8217;s address

Stealth address

allow and require the sender to create random one-time addresses for every transaction on behalf of the recipient. The recipient can publish just one address, yet have all of his/her incoming payments go to unique addresses on the blockchain, where they cannot be linked back to either the recipient&＃8217;s published address or any other transactions&＃8217; addresses.

https://getmonero.org/resources/moneropedia/stealthaddress.html

Point 2: Ring Signatures to protect the sender&＃8217;s address

a ring signature is a type of digital signature that can be performed by any member of a group of users that each have keys. Therefore, a message signed with a ring signature is endorsed by someone in a particular group of people.

https://getmonero.org/resources/moneropedia/ringsignatures.html

Point 3: Ring Confidential Transactions to hide the the exact amount

RingCT introduces an improved version of ring signatures called &＃8220;A Multi-layered Linkable Spontaneous Anonymous Group signature&＃8221;, which allows for hidden amounts, origins and destinations of transactions with reasonable efficiency and verifiable, trustless coin generation.

https://getmonero.org/resources/moneropedia/ringCT.html

Point 4: I2P to protect communication over the Internet

I2P is an anonymous overlay network &＃8211; a network within a network. It is intended to protect communication from dragnet surveillance and monitoring by third parties such as ISPs.

https://geti2p.net/en/

And worth mentioning is one another technology called Zero-knowledge Proof:

https://medium.com/@jinglan/how-to-explain-zero-knowledge-protocols-to-your-average-child-eb49feb4a41d
http://pages.cs.wisc.edu/~mkowalcz/628.pdf

关于区块链交易

您可能听说过区块链，并且一般区块链的功能之一是可跟踪性，即您跟踪所有历史交易的发件人，收件人和金额。 看看第一张图的上半部分，例如，张三向李四发送一个比特币，然后在比特币区块链中，您将看到类似以下的交易：

在这次交易中，所以我们知道173XurTkp5yBrUfg6ng2kaEk9pm4qxzu5q将0.00101883BTC转账到12iVTz5rj1TpxXvaWrWFAxNwGKiXznYvsU。 尽管我们不知道发件人和收件人是谁，但如果关联可以通过其他方式建立，那么该人所有过去和未来交易都将会公之于众。

为了解决区块链隐私问题，已经开发了一些技术来实现区块链的匿名性。 例如，看一下第一张图的下半部分，有4点可以保护隐私：

第1点：隐形地址以保护收件人的地址

隐形地址

允许并要求发件人代表收件人为每笔交易创建随机的一次性地址。 收件人只能发布一个地址，但他/她的所有付款都会转到区块链上的唯一地址，并且无法链接到收件人发布的地址或任何其他交易的地址。

https://getmonero.org/resources/moneropedia/stealthaddress.html

第2点：环形签名以保护发件人的地址

环签名是一种数字签名，可以由一组用户中的任何成员执行，每个用户都有密钥。 因此，用环签名签名的消息由特定人群中的某人签署。

https://getmonero.org/resources/moneropedia/ringsignatures.html

第3点：环机密交易以隐藏确切金额

RingCT引入了名为“多层可链接自发匿名组签名”的改进版本的环签名，该签名允许以合理的效率和可验证的无信任币生成来隐藏金额，交易的来源和目的地。

https://getmonero.org/resources/moneropedia/ringCT.html

第4点：I2P保护互联网上的通信

I2P是匿名附加网络 &＃8211; 网络内的网络。 它旨在保护通信不受第三方（如ISP）监控和监视的影响。

https://geti2p.net/en/

值得一提的还有另一项技术就是零知识证明：

https://medium.com/@jinglan/how-to-explain-zero-knowledge-protocols-to-your-average-child-eb49feb4a41d
http://pages.cs.wisc.edu/~mkowalcz/628.pdf

References (参考）：

https://getmonero.org/resources/moneropedia/
http://www.nicolascourtois.com/bitcoin/paycoin_privacy_monero_6.pdf
https://medium.com/@jinglan/how-to-explain-zero-knowledge-protocols-to-your-average-child-eb49feb4a41d
http://pages.cs.wisc.edu/~mkowalcz/628.pdf
https://geti2p.net/en/