Quote from: presstab on February 13, 2015, 01:42:58 AM

Quote from: iantunc on February 13, 2015, 12:05:00 AM

Presstab, could you describe in two words, pls, the bug in PoS you have discovered, for those who's out of topic, in a non-tech way? To let them have an understanding of what is going on behind the scenes.

Every coin has a setting "timedrift". It is meant to allow nodes that are for one reason or another a bit out of sync with the median time, to be able to submit blocks and still be fine.

For example peercoin allows a time drift of 2 hours, and same with NovaCoin. HoboNickels, BottleCaps, HyperStake are all 15 minute timedrift allowance.

So when you are attempting to stake and meet the staking target, you create 60 hashes at once per UTXO if you are using standard peercoin hashing code. The only thing that changes from hash to hash is the input for time. It hashes 60 seconds into the future at once. This system works pretty good, and doesn't really have much problem.

The problem is that when you get someone that tweaks the code, and says "why not hash 2 hours into the future" I will have 7,200 hashes to attempt to stake instead of 60 hashes". So this code tweakers chance of staking is actually 11,900% more likely to hit a hash (did I do the math correctly? I think I did).

My original thinking, and the reason I released the beta release, was that if some code tweaker has that advantage, let us even the playing field and give it to everyone. And so I released that code.

What I failed to realize is that this would really screw up difficulty. Let's say the code tweaker above hashed two hours into the future, submitted the stake, and the network accepted it with no problems. The next block would calculate difficulty by taking that 2 hour future stake and subtracting the last time before that, calculating the time to stake as 2 hours between the two blocks. The difficulty code thinks that this means that people are having trouble staking, and the diff drops.

With the new HYP code, we got diff as low as 3 i think it was (from the 10+ that it had been before), made 1,975 blocks today (compared to the target of 960), and minted 1.8 million HYP compared to our targeted 960k max.

Hope that makes some sense. Running the new code on a test network and should have it out soon.

Thanks for a very clear explanation. It's really a major issue.