1. 什么是公共区块链?
公共区块链是允许任何人参与网络的开放网络，即公共区块链是无需许可的。在这种类型的区块链中，任何人都可以加入网络并读取、写入或参与区块链。公共区块链是去中心化的，没有控制网络的单一实体。公共区块链上的数据是安全的，因为一旦在区块链上验证数据，就无法修改或更改数据。
公共区块链的一些特点是：
- 高安全性 –
由于采矿(51％规则)，它是安全的。 - 开放环境——
公共区块链对所有人开放。 - 匿名性质 –
在公共区块链中，每个人都是匿名的。无需使用您的真实姓名或真实身份，因此一切都会隐藏起来，没有人可以据此跟踪您。 - 没有规定——
公共区块链没有任何节点必须遵守的规定。因此，如何使用这个平台来改善他们的生活是没有限制的 - 完全透明 –
公共区块链允许您随时查看分类帐。没有任何腐败或任何差异的余地，每个人都必须维护分类账并参与共识。 - 真正的去中心化——
在这种类型的区块链中，没有中心化的实体。因此，维护网络的责任完全在节点上。他们正在更新账本，并在共识算法的帮助下促进公平。 - 全面的用户授权 –
通常，在任何网络中用户都必须遵守很多规章制度。在许多情况下，规则甚至可能不公平。但不是在公共区块链网络中。在这里，所有用户都被授权，因为没有中央权威来查看他们的一举一动。 - 不可变——
当某些内容写入区块链时，它无法更改。 - 分散式 –
数据库不像客户端 – 服务器方法那样集中，区块链中的所有节点都参与交易验证。
2. 什么是私有区块链?
私有区块链由网络管理员管理，参与者需要同意才能加入网络，即私有区块链是经过许可的区块链。有一个或多个实体控制网络，这导致依赖第三方进行交易。在这种类型的区块链中，只有参与交易的实体才知道所执行的交易，而其他人将无法访问它，即交易是私有的。
私有区块链的一些特点是：
- 完全隐私 –
它专注于隐私问题。 - 私有区块链更加中心化。
- 高效率和更快的交易 –
当您在本地分发节点，但参与账本的节点少得多时，性能会更快。 - 更好的可扩展性——
能够按需添加节点和服务可以为企业提供巨大的优势。
公有链和私有链的区别：
| S.no | Basis of Comparison | Public BlockChain | Private BlockChain |
|---|---|---|---|
| 1. | Access – | In this type of blockchain anyone can read, write and participate in a blockchain. Hence, it is permssionless blockchain. It is public to everyone. | In this type of blockchain read and write is done upon invitation, hence it is a permissioned blockchain. |
| 2. | Network Actors – | Don’t know each other | Know each other |
| 3. | Decentralized Vs Centralized – | A public blockchain is decentralized. | A private blockchain is more centralized. |
| 4. | Order Of Magnitude – | The order of magnitude of a public blockchain is lesser than that of a private blockchain as it is lighter and provides transactional throughput. | The order of magnitude is more as compared to the public blockchain. |
| 5. | Native Token – | Yes | Not necessary |
| 6. | Speed – | Slow | Fast |
| 7. | Transactions pre second – | Transactions per second are lesser in a public blockchain. | Transaction per second is more as compared to public blockchain. |
| 8. | Security – | A public network is more secure due to decentralization and active participation. Due to the higher number of nodes in the network, it is nearly impossible for ‘bad actors’ to attack the system and gain control over the consensus network. | A private blockchain is more prone to hacks, risks, and data breaches/ manipulation. It is easy for bad actors to endanger the entire network. Hence, it is less secure. |
| 9. | Energy Consumption – | A public blockchain consumes more energy than a private blockchain as it requires a significant amount of electrical resources to function and achieve network consensus. | Private blockchains consume a lot less energy and power. |
| 10. | Consensus algorithms – | Some are proof of work, proof of stake, proof of burn, proof of space etc. | Proof of Elapsed Time (PoET), Raft, and Istanbul BFT can be used only in case of private blockchains. |
| 11. | Attacks – | In a public blockchain, no one knows who each validator is and this increases the risk of potential collision or a 51% attack (a group of miners which control more than 50% of the network’s computing power.). | In a private blockchain, there is no chance of minor collision. Each validator is known and they have the suitable credentials to be a part of the network. |
| 12. | Effects – | Potential to disrupt current business models through disintermediation. There is lower infrastructure cost. No need to maintain servers or system admins radically. Hence reducing the cost of creating and running decentralized application (dApps). | Reduces transaction cost and data redundancies and replace legacy systems, simplifying documents handling and getting rid of semi manual compliance mechanisms. |
| 13. | Examples – | Bitcoin, Ethereum, Monero, Zcash, Dash, Litecoin, Stellar, Steemit etc. | R3 (Banks), EWF (Energy), B3i (Insurance), Corda. |