51% attack PoS

Economics Minting (Proof of Stake)
1

Hi all,

just thought about the following scenario.

One buys, let´s say 1 or 2 or 3% of all PPC and splits it. Then he keeps the wallet offline for 90 days to reach maximum coinage. When he now goes online again he has a good chance to mint 6 Blocks in a row and would therefore be able to double spent.

Did I understand soemthing wrong?

Cheers,
Muto

2

Yes, it takes 520 blocks to confirm. So he would have to mint them all …

3

Thanks for that hint :wink: However, this tactic significant reduces the amount of PPC needed to do a 51% attack. It’s by far not 51% of all PPC. Neither it’s 51% of coins with >30 Days coinage. Correct?

Do you know how often a PoS block is created on average?

4

There are a lot more PoS blocks than Pow. Once you mint a block with your coins they are locked in stake for 520 blocks, and the PoS mints with a transactions size ie if you get 1000PPC and the transaction is old enough it will mint and your PPCs will be locked in stake. There is no guarantee that the next block will be PoS so you have to own 51% PoW, and if you have a bunch of old coins there is no guarantee that you find all the PoS blocks in a row either … So NO finding six blocks and double spending might risk the network rejecting your blocks and losing your stake…

5

Sakhan, thanks for pointing that out. So even 51% PoS blocks do not give you the control of the chain. You have to have 51% of all minting power (PoS and PoW)

6

But wouldn’t this be true when the system eventually transitions to 100% POS?

7

Now you know the checkpoint is good for something – for PPC it is possible to roll back the bad transactions with the check point. That is a significant concern for any potential attackers – why waste so much effort to run into a wall?