Pools and the 51% attack

[azulene]

So I think I know what the 51% attack is, it's when someone takes over a network with more than 51% of the hash rate and can control what transactions do / don't get rejected and has the option to do dodgy stuff.

So last night I was dabbling with mining mincoin and now franko and the pools I was at have been getting close to 100% (occasionally over 100%) of the overall network hash rate.

Is this not by definition a 51% attack? Actually a 99%+ attack?

Doesn't the security of the currency depend on proper decentralization? This is not quite decentralized, I think..

[jp333]

Here's the current breakdown. I don't think anyone's been close to 50%:
https://blockchain.info/pools

[Foxpup]

Yes, many altcoins are at extreme risk of a 51% attack due to both the small number of mining pools and low overall hashrate.

Is this not by definition a 51% attack? Actually a 99%+ attack?

No, but it means that the pool can carry out a 51% attack immediately if the pool operator decides to do so, or the pool server is hacked. The security of the currency is entirely dependent on a single person. Something to think about if you're going to dabble in altcoins.

[PangPang]

You can refer to the wiki.
https://en.bitcoin.it/wiki/Weaknesses#Attacker_has_a_lot_of_computing_power

[b!z]

So I think I know what the 51% attack is, it's when someone takes over a network with more than 51% of the hash rate and can control what transactions do / don't get rejected and has the option to do dodgy stuff.

So last night I was dabbling with mining mincoin and now franko and the pools I was at have been getting close to 100% (occasionally over 100%) of the overall network hash rate.

Is this not by definition a 51% attack? Actually a 99%+ attack?

Doesn't the security of the currency depend on proper decentralization? This is not quite decentralized, I think..

The pool owners could carry out an attack, but apparently they have chosen not to.