<p>Obviously the block author selection cannot be random if all network participants must converge on the same choice. In some systems, the selection is based on previous blockdata which is assumed to have pseudorandom properties and is already agreed upon. Some of these approaches are considered gameable, but it appears that many networks have come to the conclusion that POS is unreliable in absence of a coordinating entity anyway.</p>
<blockquote>
<p>The question is what happens if a stakeholder manipulates the client application, such that he could always be elected as a validator?</p>
</blockquote>
<p>Under the premise that &quot;the system is not centralized&quot;, what you do with your own node software has zero bearing on other nodes. When you manipulate your own node to follow different protocol rules, you most likely just fork off from the network which has no impact on the remaining network whatsoever.</p>

CC BY-SA 4.0
2020-09-17T19:45:13.013Z
So my point of view is not very precise on functionality of PoS ... Could you please mention any reference explaining about this **pseudorandom blockdata**? Thanks
Questioner
CC BY-SA 4.0
2020-09-17T19:55:12.067Z
Blocks are usually represented with the hash of their header. The output of a hash function is deterministic in that it will always have the same outcome for the same input, but the output is uniformly distributed in the projection space and cannot be predicted before performing the hash for the first time. Therefore, the block hash can be used as a pseudorandom source.
Murch
CC BY-SA 4.0
2020-09-17T19:58:56.187Z
"So my point of view is not very precise on functionality of PoS" ⇒ that's because POS is a consensus approach and there are many different implementations of it. It's difficult to give a precise answer to a vague question.
Murch
CC BY-SA 4.0
2020-09-17T20:01:31.730Z
Yes, but how the block hash can affect selection of the next block's author? (If you also know any document explaining the process (any arbitrary protocol which uses such a process),  it would be perfect.) Thanks
Questioner
CC BY-SA 4.0
2020-09-17T20:04:49.180Z
I don't remember the details, I don't find POS particularly relevant or interesting. I would suggest searching for the Peercoin whitepaper or announcement, or reading the Ethereum Casper documentation.
Murch
CC BY-SA 4.0
2020-09-17T20:07:15.243Z
I'm honestly curious, though. You've been asking questions here for years, about rather obscure topics but missing fairly well-known facts or details in the context. Where are all these questions coming from? How did you arrive at all these special topics but skipped over all the basic concepts?
Murch
CC BY-SA 4.0
2020-09-17T20:15:59.673Z
I well know most dominant blockchain protocols, but it is normal that nobody knows anything about a field, particularly, when there are too many different protocols (as for example you don't remember the details of block' author selection process ... I have read like you Peercoins years ago ...) even in the case of  PoS, "random selection of block's author" is a common (but not precise) opinion ... Most people concentrate on only one protocol (only Bitcoin, or only Ethereum or ...) but I'd like to investigate all important proposals on the blockchain ...
Questioner
CC BY-SA 4.0
2020-09-17T20:19:31.800Z
I'm sure even many smart contract developers don't know yet how to select the next block's author in detail ...
Questioner
CC BY-SA 4.0
2020-09-17T20:28:17.360Z
I'd also like to add that one of the results of those questions is that I found out that there are huge misconceptions on the blockchain ...
Questioner
CC BY-SA 4.0
2020-09-17T19:13:36.383Z
2020-09-17T19:19:25.937Z
2020-09-17T19:19:25.937Z
Murch
<p>In proof-of-stake, by definition, each stakeholder deposits and locks some tokens (stakes) for more chances to be selected as an author of block in a random-based election procedure.</p>
<p>Till here, it's clear.</p>
<p>But, as the system is not centralized and there is no server which would do the election procedure, each stakeholder installs a client application on their machine to do the random-based selection procedure.</p>
<p>The question is what happens if a stakeholder manipulates the client application, such that he could always be elected as an author of block?</p>
<p>In other words, who (or which entity) does the random election procedure in each round?</p>
<p><strong>P.S.</strong> If the question is not still clear enough, please let me know.</p>
<p> </p>

<proof-of-stake>
Proof-of-Stake: How to prevent someone from being always selected as an author of block?
Questioner
# Proof-of-Stake: How to prevent someone from being always selected as an author of block?

(Asked by: username_0 on 2020-09-17)

In proof-of-stake, by definition, each stakeholder deposits and locks some tokens (stakes) for more chances to be selected as an author of block in a random-based election procedure.

Till here, it's clear.

But, as the system is not centralized and there is no server which would do the election procedure, each stakeholder installs a client application on their machine to do the random-based selection procedure.

The question is what happens if a stakeholder manipulates the client application, such that he could always be elected as an author of block?

In other words, who (or which entity) does the random election procedure in each round?

**P.S.** If the question is not still clear enough, please let me know.

**Tags:** proof-of-stake


---

## 1 answers

### Answer by username_1 on 2020-09-17. Score: 1

Obviously the block author selection cannot be random if all network participants must converge on the same choice. In some systems, the selection is based on previous blockdata which is assumed to have pseudorandom properties and is already agreed upon. Some of these approaches are considered gameable, but it appears that many networks have come to the conclusion that POS is unreliable in absence of a coordinating entity anyway.

> The question is what happens if a stakeholder manipulates the client application, such that he could always be elected as a validator?

Under the premise that "the system is not centralized", what you do with your own node software has zero bearing on other nodes. When you manipulate your own node to follow different protocol rules, you most likely just fork off from the network which has no impact on the remaining network whatsoever.

> **Comments:**
> **username_0**: So my point of view is not very precise on functionality of PoS ... Could you please mention any reference explaining about this **pseudorandom blockdata**? Thanks  
> **username_1**: Blocks are usually represented with the hash of their header. The output of a hash function is deterministic in that it will always have the same outcome for the same input, but the output is uniformly distributed in the projection space and cannot be predicted before performing the hash for the first time. Therefore, the block hash can be used as a pseudorandom source.  
> **username_1**: "So my point of view is not very precise on functionality of PoS" ⇒ that's because POS is a consensus approach and there are many different implementations of it. It's difficult to give a precise answer to a vague question.  
> **username_0**: Yes, but how the block hash can affect selection of the next block's author? (If you also know any document explaining the process (any arbitrary protocol which uses such a process),  it would be perfect.) Thanks  
> **username_1**: I don't remember the details, I don't find POS particularly relevant or interesting. I would suggest searching for the Peercoin whitepaper or announcement, or reading the Ethereum Casper documentation.  
> **username_1**: I'm honestly curious, though. You've been asking questions here for years, about rather obscure topics but missing fairly well-known facts or details in the context. Where are all these questions coming from? How did you arrive at all these special topics but skipped over all the basic concepts?  
> **username_0**: I well know most dominant blockchain protocols, but it is normal that nobody knows anything about a field, particularly, when there are too many different protocols (as for example you don't remember the details of block' author selection process ... I have read like you Peercoins years ago ...) even in the case of  PoS, "random selection of block's author" is a common (but not precise) opinion ... Most people concentrate on only one protocol (only Bitcoin, or only Ethereum or ...) but I'd like to investigate all important proposals on the blockchain ...  
> **username_0**: I'm sure even many smart contract developers don't know yet how to select the next block's author in detail ...  
> **username_0**: I'd also like to add that one of the results of those questions is that I found out that there are huge misconceptions on the blockchain ...  

---

