<p>Absolutely. When a coin is secured by proof of work, if there is insufficient proof of work, the coin is not secure.</p>

CC BY-SA 3.0
2014-02-04T13:32:14.807Z
What kind of protection exist? I've heard about PoW, PoS, alphabet blizzard....
user2496
CC BY-SA 3.0
2014-02-04T13:26:43.883Z
2014-02-04T13:26:43.883Z
David Schwartz
<p>I'm discovering alt-coins.</p>

<p>Now, I'm on <a href="https://cryptocointalk.com/topic/3054-piratecoin-ptc-information/" rel="nofollow">piratecoin</a>.</p>

<pre><code>{
    "blocks" : 34167,
    "currentblocksize" : 1225,
    "currentblocktx" : 1,
    "difficulty" : 0.14348426,
    "errors" : "",
    "generate" : true,
    "genproclimit" : -1,
    "hashespersec" : 355,
    "networkhashps" : 11127177,
    "pooledtx" : 1,
    "testnet" : false
}
</code></pre>

<p>There is somehow calculated <code>networkhashps</code>, seems it is aproximation from <code>difficulty</code>, it is 11,127,177, ~ 11mh/s. I'm count on my own, <code>350h/s</code>, however, <code>cgminer</code> show me <code>180Kh/s</code>. Probably it doesn't counts in <code>getmininginfo</code> or recalculated somehow. Anybody?</p>

<p>I've seen persons with much greater speed, its called mining rig. 20-30 may be 100 GPU in a bunch. </p>

<p>What if such huge miner connect to such young alt-coin network, download whole of current blockchain, and start mining off-line. After 5 hours he come back to network, his blockchain will be with bigger <code>difficulty</code>. </p>

<p>Can he attack network in such way?</p>

CC BY-SA 3.0
2014-02-04T11:45:30.473Z
Yes, read for example [CoinDesk: Feathercoin hit by massive attack](http://www.coindesk.com/feathercoin-hit-by-massive-attack/)
Murch
<security>
Hash speed attack
user2496
# Hash speed attack

(Asked by: username_0 on 2014-02-04)

I'm discovering alt-coins.

Now, I'm on [piratecoin](https://cryptocointalk.com/topic/3054-piratecoin-ptc-information/).

```
{
    "blocks" : 34167,
    "currentblocksize" : 1225,
    "currentblocktx" : 1,
    "difficulty" : 0.14348426,
    "errors" : "",
    "generate" : true,
    "genproclimit" : -1,
    "hashespersec" : 355,
    "networkhashps" : 11127177,
    "pooledtx" : 1,
    "testnet" : false
}

```

There is somehow calculated `networkhashps`, seems it is aproximation from `difficulty`, it is 11,127,177, ~ 11mh/s. I'm count on my own, `350h/s`, however, `cgminer` show me `180Kh/s`. Probably it doesn't counts in `getmininginfo` or recalculated somehow. Anybody?

I've seen persons with much greater speed, its called mining rig. 20-30 may be 100 GPU in a bunch.

What if such huge miner connect to such young alt-coin network, download whole of current blockchain, and start mining off-line. After 5 hours he come back to network, his blockchain will be with bigger `difficulty`.

Can he attack network in such way?

**Tags:** security

> **Comments:**
> **username_1**: Yes, read for example [CoinDesk: Feathercoin hit by massive attack](http://www.coindesk.com/feathercoin-hit-by-massive-attack/)  

---

## 1 answers

### Answer by username_2 on 2014-02-04. Score: 1

Absolutely. When a coin is secured by proof of work, if there is insufficient proof of work, the coin is not secure.

> **Comments:**
> **username_0**: What kind of protection exist? I've heard about PoW, PoS, alphabet blizzard....  

---

