<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


---

## 1 answers

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

In case of fork, according to [whitepaper](https://archive.org/stream/PPCoinPaper/ppcoin-paper_djvu.txt), 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](https://github.com/ppcoin/ppcoin/blob/5ace24f056a06e37352c0dd861be8ab195aceaf8/src/main.h#L1269) 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.  

---

