Someone asked me this via email, I thought I'd post the answer for everyone:
I'm looking for some clarity on the amount of Darkcoins that will be minted. I've read some where that it is something quite large. I'm looking to invest founds into emerging crypto's that have a possibility of longevity. I'm very concerned thought with the total number of coins that will be minted. Please advise. thanks.
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DarkCoin is unique in the since that it has a variable block reward that is based on difficulty. This means that while currently the block reward is 120, when difficulty rises the block reward will fall. Eventually the block reward will be driven down to it's lowest amount which is 15DRK. After that, every 2 years the block reward is halved again. So in 2 years, 7.5DRK, in 4 years, 3.75DRK, etc.
So, we don't know how many there will be, but it definitely won't reach anywhere near 84 million. It mostly depends on how long it takes us to reach the lower block reward cap. At this of rate of growth that should happen this month (it happens at about 100 difficulty).
I've read that variable block rewards are exploitable from "dishonest miners" in coins like dogecoin who switchover when the rewards are low. Could that happen to Darkcoin also? If yes then it is tempting for someone to take Darkcoin code, clone it and say "a better and improved Darkcoin, safe from dishonest mining tacticts" etc.
So, without getting insanely technical, Doge and DarkCoin are setup differently. The block reward function in DarkCoin is set on a very even curve and reward is higher toward the beginning. Later on people will forget that it was ever not fixed and they'll just talk about the halving. So there's not anything to really take advantage of, right? After a difficulty of 100, no matter what the blocks will return 15 DRK.
When I wrote the reply to the email earlier, I was thinking we'd hit 100 difficulty in a few weeks, but we're already at 600Mh/s for the network (up from 200 yesterday). If this keeps up we'll have a difficulty of 21 tomorrow and we only need 5x the growth of the network to reach that lower cap.
So I guess it's a question of incentives, knowing that we're going to cap at some point who wouldn't mine right now? From an economics point of view it's a feedback loop and it should actually make the growth exponential.