<p>A really quick answer is this: The proof of work system is a solution to the distributed synchronization issue; in another guise it is called the <a href="http://en.wikipedia.org/wiki/Byzantine_fault_tolerance">Byzantine Generals' Problem</a>. Thus, any solution to this problem is an acceptable alternative, however the proof-of-work solution is particularly suited to distributed systems.</p>

<p>You can read Satoshi Nakamoto's discussion of this <a href="http://www.mail-archive.com/cryptography@metzdowd.com/msg09997.html">here</a>.</p>

CC BY-SA 3.0
2013-03-20T20:20:15.667Z
2013-03-20T20:35:31.617Z
2013-03-20T20:35:31.617Z
Rooke
<p>I have been researching on blockchain for sometime now and some of them I found are a mix of some existing and some proposed. </p>

<ol>
<li>Proof-of-Stake </li>
<li>Proof-of-Burn</li>
<li>Proof-of-Capacity </li>
<li>Proof-of-Activity      </li>
<li>Proof-of-Checkpoint</li>
</ol>

<p>Source: <a href="https://bytecoin.org/blog/proof-of-activity-proof-of-burn-proof-of-capacity/" rel="nofollow noreferrer">https://bytecoin.org/blog/proof-of-activity-proof-of-burn-proof-of-capacity/</a></p>

CC BY-SA 3.0
2018-04-22T21:59:06.650Z
Link is dead. https://web.archive.org/web/20160304055454/https://bytecoin.org/blog/proof-of-activity-proof-of-burn-proof-of-capacity/
cp.engr
CC BY-SA 3.0
2017-01-05T08:50:44.010Z
2017-01-05T08:50:44.010Z
trollster
<p>Another alternative is <a href="https://en.bitcoin.it/wiki/Proof_of_burn" rel="noreferrer">proof of burn</a>.</p>

CC BY-SA 3.0
2013-05-08T12:15:14.777Z
2013-05-08T12:15:14.777Z
Fernando N.
<p>Bitcoin uses proof of work to secure the network, Ripple uses a global consensus system and PPCoin uses proof of stake.</p>

<p>Are there any known alternatives to the above methods?</p>

CC BY-SA 3.0
2013-03-20T19:33:59.747Z
in the ppc paper they talk about a 'proof of excellence' where all peers compete to solve a game. It is basically proof of work, buta better algorithm could score higher.
placeybordeaux
CC BY-SA 3.0
2013-03-21T03:50:36.520Z
@David Perry. This is a subtly different question than what you've suggested as a duplicate. This person is asking if there exist alternative distributed synchronization algorithms. The other question asks if the proof-of-work system can prove secondarily-useful work. There is a clear difference.
Rooke
CC BY-SA 3.0
2013-03-21T05:08:59.270Z
@Rooke fair enough, I'll re-open it.
David Perry
CC BY-SA 3.0
2013-09-28T15:40:44.353Z
possible duplicate of [Is there a way to set up proof-of-work systems so it would be even more useful?](http://bitcoin.stackexchange.com/questions/331/is-there-a-way-to-set-up-proof-of-work-systems-so-it-would-be-even-more-useful)
Stephen Gornick
<security><doublespend><proof-of-work><proof-of-stake><consensus>
Are there alternatives for proof of work?
Maestro
# Are there alternatives for proof of work?

(Asked by: username_0 on 2013-03-20)

Bitcoin uses proof of work to secure the network, Ripple uses a global consensus system and PPCoin uses proof of stake.

Are there any known alternatives to the above methods?

**Tags:** security, doublespend, proof-of-work, proof-of-stake, consensus

> **Comments:**
> **username_1**: in the ppc paper they talk about a 'proof of excellence' where all peers compete to solve a game. It is basically proof of work, buta better algorithm could score higher.  
> **username_2**: @username_3. This is a subtly different question than what you've suggested as a duplicate. This person is asking if there exist alternative distributed synchronization algorithms. The other question asks if the proof-of-work system can prove secondarily-useful work. There is a clear difference.  
> **username_3**: @username_2 fair enough, I'll re-open it.  
> **username_4**: possible duplicate of [Is there a way to set up proof-of-work systems so it would be even more useful?](http://bitcoin.stackexchange.com/questions/331/is-there-a-way-to-set-up-proof-of-work-systems-so-it-would-be-even-more-useful)  

---

## 3 answers

### Answer by username_7 on 2013-05-08. Score: 5 | Accepted answer

Another alternative is [proof of burn](https://en.bitcoin.it/wiki/Proof_of_burn).


---

### Answer by username_2 on 2013-03-20. Score: 6

A really quick answer is this: The proof of work system is a solution to the distributed synchronization issue; in another guise it is called the [Byzantine Generals' Problem](http://en.wikipedia.org/wiki/Byzantine_fault_tolerance). Thus, any solution to this problem is an acceptable alternative, however the proof-of-work solution is particularly suited to distributed systems.

You can read Satoshi Nakamoto's discussion of this [here](http://www.mail-archive.com/cryptography@metzdowd.com/msg09997.html).


---

### Answer by username_5 on 2017-01-05. Score: 2

I have been researching on blockchain for sometime now and some of them I found are a mix of some existing and some proposed.

1. Proof-of-Stake
2. Proof-of-Burn
3. Proof-of-Capacity
4. Proof-of-Activity
5. Proof-of-Checkpoint

Source: <https://bytecoin.org/blog/proof-of-activity-proof-of-burn-proof-of-capacity/>

> **Comments:**
> **username_6**: Link is dead. https://web.archive.org/web/20160304055454/https://bytecoin.org/blog/proof-of-activity-proof-of-burn-proof-of-capacity/  

---

