<blockquote>
  <p>What is the reason? And Is it logical to use "Proof-of-Authority" for a "public" blockchain, in sense of keeping decentralization?</p>
</blockquote>

<p>Proof of Authority is, by definition, centralised. If the authority nodes go rogue, or fail to reach consensus, the network is useless. </p>

<p>You could use it in public networks (some of the ethereum testnets are PoA), but it would not be a decentralized network. The value of a PoA mainnet would have to come from some benefit of its centralization, and a very high level of trust in the trusted authorities.</p>

CC BY-SA 4.0
2018-07-27T09:45:04.497Z
2018-07-27T09:45:04.497Z
Raghav Sood
<p>Proof Of Authority was developed primarily as a solution to the problem of spam attacks on Ethereum’s Ropsten test network.It's the optimised version of Proof Of Stake by leveraging identity as the form of stake.</p>

<p>The basic principle behind this is</p>

<blockquote>
  <p>"It takes 20 years to build a reputation and 5 minutes to ruin it. If 
  you think about that, you’ll do things differently."</p>
</blockquote>

<p>POA consensus aren't 100% decentralised but rather a compromise between decentralization and the efficiency afforded by centralization.</p>

<p>Disadvantage is some people simply do not care about their
   reputation .If validators that is limited in number, they are
   subjected to outside influence from third parties, especially if
   those third parties have a significant interest in seeing the network
   fail then it may lead to disaster.</p>

<p>So in a nutshell POA is good for private blockchains with centralized
   trusted authority.</p>

CC BY-SA 4.0
2018-09-07T16:54:12.410Z
2018-09-07T16:54:12.410Z
VforVendetta
<p>According <a href="https://wiki.parity.io/Proof-of-Authority-Chains" rel="nofollow noreferrer">parity.io</a> website: </p>

<blockquote>
  <p>Proof-of-Authority is a replacement for Proof-of-Work, which can be
  used for <strong>private</strong> chain setups.</p>
</blockquote>

<p>And also:</p>

<blockquote>
  <p>The chain has to be signed off by the majority of authorities, in
  which case it becomes a part of the permanent record. This makes it
  easier to maintain a <strong>private</strong> chain and keep the block issuers
  accountable.</p>
</blockquote>

<p>And also:</p>

<blockquote>
  <p>PoA networks are well-suited to regulated industries where entities
  responsible for maintaining the network (authorities) need to be
  <strong>known</strong>, rather than remain <strong>anonymous</strong> as in mining-based chains like
  Bitcoin and Ethereum.</p>
</blockquote>

<p>It is <strong>underlined</strong> to use <code>Proof-of-Authority</code> for a <strong>private</strong> chain.</p>

<p>What is the reason? And Is it logical to use "Proof-of-Authority" for a "<strong>public</strong>" blockchain, in sense of keeping <strong>decentralization</strong>?</p>

<blockchain><privacy><consensus><decentralization><private-blockchains>
Is it logical to use “Proof-of-Authority” for a “public” blockchain?
Questioner
# Is it logical to use “Proof-of-Authority” for a “public” blockchain?

(Asked by: username_0 on 2018-07-27)

According [parity.io](https://wiki.parity.io/Proof-of-Authority-Chains) website:

> Proof-of-Authority is a replacement for Proof-of-Work, which can be
> used for **private** chain setups.

And also:

> The chain has to be signed off by the majority of authorities, in
> which case it becomes a part of the permanent record. This makes it
> easier to maintain a **private** chain and keep the block issuers
> accountable.

And also:

> PoA networks are well-suited to regulated industries where entities
> responsible for maintaining the network (authorities) need to be
> **known**, rather than remain **anonymous** as in mining-based chains like
> Bitcoin and Ethereum.

It is **underlined** to use `Proof-of-Authority` for a **private** chain.

What is the reason? And Is it logical to use "Proof-of-Authority" for a "**public**" blockchain, in sense of keeping **decentralization**?

**Tags:** blockchain, privacy, consensus, decentralization, private-blockchains


---

## 2 answers

### Answer by username_1 on 2018-07-27. Score: 3

> What is the reason? And Is it logical to use "Proof-of-Authority" for a "public" blockchain, in sense of keeping decentralization?

Proof of Authority is, by definition, centralised. If the authority nodes go rogue, or fail to reach consensus, the network is useless.

You could use it in public networks (some of the ethereum testnets are PoA), but it would not be a decentralized network. The value of a PoA mainnet would have to come from some benefit of its centralization, and a very high level of trust in the trusted authorities.


---

### Answer by username_2 on 2018-09-07. Score: 0

Proof Of Authority was developed primarily as a solution to the problem of spam attacks on Ethereum’s Ropsten test network.It's the optimised version of Proof Of Stake by leveraging identity as the form of stake.

The basic principle behind this is

> "It takes 20 years to build a reputation and 5 minutes to ruin it. If
> you think about that, you’ll do things differently."

POA consensus aren't 100% decentralised but rather a compromise between decentralization and the efficiency afforded by centralization.

Disadvantage is some people simply do not care about their
reputation .If validators that is limited in number, they are
subjected to outside influence from third parties, especially if
those third parties have a significant interest in seeing the network
fail then it may lead to disaster.

So in a nutshell POA is good for private blockchains with centralized
trusted authority.


---

