Man, what's up with our POW difficulty right now? 26006 - and it's been over an hour since the last block as a result. Crazy.
I don't understand this obsession with PoW difficulty. Difficulty goes up and down to keep the average blocktime as close to 7 minutes as possible. Since network hashrate changes and time to produce an acceptable hash is not guaranteed, you will see fluctuation of blocktime and difficulty. Ideally, you want the smallest gap between min & max time between blocks but this not possible with proof-of-work algorithm.
Well, I'm not sure I'd go with the word "obsession" - but let me explain why it is interesting. The sliding scale of difficulty to hit 7 minute blocks is obvious and uninteresting - however, you said it yourself, that the network hashrate changes. The comment is roughly equivalent to "wow, our network hashrate 2 hours ago must have been much much higher than now, because our difficulty is high and it has taken a long time to get a block as a result - meaning that the difficulty will again soon slide back down to adapt to the fact that our network hashrate has shrunk."
What it does it tell us some things about who is mining when. If the network hash suddenly increases such that our difficulty triples for an hour or two and then goes back down, how is that not a conversation topic? Nobody who has that much hash power is doing this adhoc, which means we have the part-time attention of some very big players. I find that a worthy note and a good discussion point. I do NOT find "DUH, 7 minute blocks!" to be an interesting point, but I guess to each their own.
If the network hash rate is suddenly increasing for a short time, someone could very well be attempting a 51% attack to try and attempt to induce the ability to double spend.
Rob, what are the controls that make sure this doesn't happen? What prevents someone from registering a CPID with Rosetta and then spinning up as many heat miners as they can to try and gain 51% or more of the network hash rate? They don't have the incentive to heat mine for reward but they have an incentive to attack and double spend.
I don't yet know as much about this as I should, but doesn't the chain have to fork for a 51% attack and an attempt at double spend (spending currency the attacker did not earn) to be successful? So at 51% of the hash rate the attacker has the ability to enforce their own version of the blockchain, which in their own version, they could give themselves as much coin as they wanted. Couldn't we use the masternodes as trusted nodes to check for forks in the chain or unauthorized changes in the chain to prevent a successful 51% attack? Can you explain the security we have against a 51% attack? Thanks, Rob.
We have better 51% attack protection than bitcoin but we are cheaper to attack (being smaller). Bitcoin has the problem of concentrated asics owned by a small quantity of miners that could collude together to attack. We have the broad base of 2500 pc's, which are more likely to be decentralized. So that part is the run of the mill answer (IE pc based vs ASIC based).
However what we have added that makes it a magnitude harder to attack us is we require a distinct CPID to solve each block, and the CPID must have magnitude. Every 4th block we clear the buffer and allow (the old CPID to start again). This means we effectively break the ability to solve consecutive blocks. Of course you could own more than one CPID with mag, but you would need to buy 51% of the CPID pool, and thats a lot of research, in order to add an effective attack vector on top of the one above (IE the classic 51%). So in our case it looks like a 51% attack would be : 51% of the CPIDs, with magnitude, running on 51% * 2500 PC's (heat mining portion) - heat mining PCs running boinc with at least 250 CPIDs (based on last superblock of 524 researchers) with magnitude. It would be an expensive attack. We also have DGW (dark gravity wave) which increases the diff during an attack.
If the perpetrator were trying to issue a coinbase, they would need 100 confirms, which is pretty much impossible. I don't want to discuss this publically to give any more ideas to any large whales and fuel the fire with any chance of putting our coin at risk.
