Quote from: Balthazar on February 25, 2014, 09:38:32 AM

Quote from: Nullu on February 20, 2014, 08:14:43 AM

Quote from: Zukii on February 20, 2014, 08:09:55 AM

Quote from: publicjud on February 20, 2014, 01:32:33 AM

So after the PoW phase, (3 weeks) then block reward is only 1 coin. And then all PoS minting. But to mint PoS you only need to turn on your wallet once every 20 days. So who will be running the block chain (securing transactions) after PoW phase?

this is what i was wondering too.
i assume its still PoW from miners, but with no one mining (or very few) it would be very easy to 51%.

someone please correct if I'm wrong

PoS takes over as the dominant mining process, and as coins age at from the point they were mined, someone will always be minting somewhere to generate new network blocks. To 51% attack with PoS you'd need to hold 51% or more of all Mint,

False.

Quote from: Balthazar on February 24, 2014, 08:49:51 PM

Quote from: New_Hampshire on February 24, 2014, 04:33:38 AM

This is not true. Similar to PoW

That's a false statement. Proof-of-Stake isn't similar to Proof-of-Work because it's cost-free. Unlike Proof-of-Work, you can retry attack attempts multiple times using the same coins.

Quote from: New_Hampshire on February 24, 2014, 04:33:38 AM

thats subject to a 51% attack, the PoS will need to hold 51% coins in order to be able to attack the coin. But holding 51% and then attacking your own coin normally is not in your interests.

You don't need 51% of coins to perform a successful attack. You only need less than 15% of active weight here.

Code:

ATTEMPTS = 1 / STAKE ^ CONFIRMATIONS

If you have 25% of active weight then you need ~256 attempts;
If you have 15% of active weight then you need ~1975 attempts;
If you have 10% of active weight then you need ~10000 attempts.

Note that active weight has no direct relation with total supply. It's calculated as (volume * timeweight) for coins participating in the network protection. E.g. if there are only 50% of coins @ maximum timeweight used for stake generation, then you need ~7.5% of total coins volume in order to perform double-spend attack for the reasonable time.

Please elaborate for us newbs, for example what is active weight? Or timeweight?
Coins participating in the network protection = mining plus opened wallets?
So when PoW is "done", there will be 20 billion coins total. 7.5% of that would be 1.5 billion. That would be enough to successfully doublespend? Still big but not impossible numbers.