<p>In case of fork, according to <a href="https://archive.org/stream/PPCoinPaper/ppcoin-paper_djvu.txt" rel="nofollow">whitepaper</a>, the chain with highest consumed coin age wins:</p>

<blockquote>
  <p>The protocol for determining which competing block chain wins as main
  chain has been  switched over to use consumed coin age. Here every
  transaction in a block contributes its consumed coin age to the score
  of the block. The block chain with highest total consumed coin age is
  chosen as main chain.</p>
</blockquote>

<p>In actual implementation, sightly <a href="https://github.com/ppcoin/ppcoin/blob/5ace24f056a06e37352c0dd861be8ab195aceaf8/src/main.h#L1269" rel="nofollow">more complicated algorithm</a> based on PoS difficulty is used:</p>

<pre><code>PoS_block_trust = 2^256 / (target+1)
PoW_block_trust = 1
</code></pre>

<p>And the chain with highest total "trust" is preferred.</p>

<p>So, the answer to your question is: PoS block wins.</p>

CC BY-SA 3.0
2014-08-10T04:47:03.180Z
What is the maximum possible value of target? Could target ever equal 2^256, thereby pushing PoS_block_trust below 1?
pankajsg
CC BY-SA 3.0
2014-08-12T13:50:33.030Z
Even if it can, `target=2^256` means any hash is acceptable, so the block will be mined almost instantly (both PoS and PoW), and the target will be readjusted *very* soon, so it's not of much concern anyway.
aland
CC BY-SA 3.0
2014-08-01T12:36:06.570Z
2014-08-01T12:36:06.570Z
aland
<p>In other words, if one user is trying to find a block using staked coins and another using PoW, which one will find it and why? Will there be a fork in the blockchain in this scenario? If yes, then how does the network decide which chain to accept? </p>

<p>I have a fairly good understanding of proof-of-work, and am trying to understand proof-of-stake correctly as well.</p>

<proof-of-stake><peercoin>
Peercoin proof-of-stake: When a person with large computing power and a person with a large stake both compete to generate a new block who wins?
pankajsg
# Peercoin proof-of-stake: When a person with large computing power and a person with a large stake both compete to generate a new block who wins?

(Asked by: username_0 on 2014-07-30)

In other words, if one user is trying to find a block using staked coins and another using PoW, which one will find it and why? Will there be a fork in the blockchain in this scenario? If yes, then how does the network decide which chain to accept?

I have a fairly good understanding of proof-of-work, and am trying to understand proof-of-stake correctly as well.

**Tags:** proof-of-stake, peercoin


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## 1 answers

### Answer by username_1 on 2014-08-01. Score: 2 | Accepted answer

In case of fork, according to whitepaper, the chain with highest consumed coin age wins:

The protocol for determining which competing block chain wins as main
  chain has been  switched over to use consumed coin age. Here every
  transaction in a block contributes its consumed coin age to the score
  of the block. The block chain with highest total consumed coin age is
  chosen as main chain.

In actual implementation, sightly more complicated algorithm based on PoS difficulty is used:
PoS_block_trust = 2^256 / (target+1)
PoW_block_trust = 1

And the chain with highest total "trust" is preferred.
So, the answer to your question is: PoS block wins.

> **Comments:**
> **username_0**: What is the maximum possible value of target? Could target ever equal 2^256, thereby pushing PoS_block_trust below 1?  
> **username_1**: Even if it can, `target=2^256` means any hash is acceptable, so the block will be mined almost instantly (both PoS and PoW), and the target will be readjusted *very* soon, so it's not of much concern anyway.  

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