An important technical question about mining.

[no-ice-please]

i would be grateful for an advice/opinions.

Recently 1credit has had some strange problems.

There were no blocks found for more than a month. A person could go to the network tab at https://chainz.cryptoid.info/1cr/ and see the expected miners who control the network, they are known nodes listed publicly.

Then one day, all of a sudden, the explorer was showing that in fact there were blocks created during that period. 6,000 blocks in fact. More than 10% of the entire coin supply was created in the blink of an eye.

This does not look right.

If anybody has any suggestions they would be welcome. I own a lot of 1credit but now am being portrayed as having sabotaged it or something for pointing out what looks like a serious problem.

Is it not really a problem? Is it normal for blocks to appear like that? Or am I exaggerating the seriousness of the problem? Does anybody know a fix for the algorithm of coins like that with Kimoto gravity wave etc?

https://bitcointalk.org/index.php?topic=645124

[bathrobehero]

At first sight it just looks like the block explorer's node was offline and after a month it reconnected and synced to the real network.

That could have happened is the owner of the block explorer didn't update the wallet (in case there was a mandatory update).

Or the block explorer's node might have been on a fork.

[no-ice-please]

At first sight it just looks like the block explorer's node was offline and after a month it reconnected and synced to the real network.

That could have happened is the owner of the block explorer didn't update the wallet (in case there was a mandatory update).

Or the block explorer's node might have been on a fork.

The block explorer showed a list of nodes, including ones that are known as reliable mining nodes for the coin several times in that period that I checked.

Also one pool reported that difficulty seemed to be an astronomical number, a few hundred thousand, rather than about a hundred.

The coins that appeared suddenly, more than ten percent of the current supply now, seem to have been mined by one miner.

The dev thinks this is an issue that may affect other Kimoto gravity coins etc, I do not know anything about that stuff.

[bathrobehero]

I see. It might have been a block withholding attack where a miner was mining blocks but not submitting them to the network for a period of time.

The problem with single algorithm coins is that it's impossible for any difficulty retargeting mechanism to keep the network steady because all of them can only change the difficulty once a block is found. Which means the difficutly could get kicked so high the blockchain stops or if the difficulty increase is limited then mining with excessive hashrate results in rapid block mining rate so the miner will mine way more blocks than it was intended.

Especially since ASICs, if a coin isn't mined by a lot of miners, a single ASIC user with tons of hashrate can start cause the difficulty retarget to overcompensate, kicking the difficulty really high.

So when the big miner leaves the difficulty stays super high because small miners (or no miners) will not be able to find blocks anytime soon.


So the diff is super high so mining is unprofitable so the blockchain halts. Meanwhile a miner could keep mining without sending his found blocks to the network.

If he can find blocks even at high difficulty he can then easily lower the difficulty by slowly lowering his hashing speed and eventually he could find all the blocks for himself even with a very old CPU because of the difficulty retarget in place.


Once he's far enough and mined a huge amount of blocks (and is ahead of the other network in terms of block height), he can realease his mined blocks to the wild and since he has the longest chain the network will generally accept it.

This issue will be more and more prevalent with single algorithm coins.

This can be mitigated with checkpoints and central nodes somewhat but that's kind of a bandaid solution.


Adding multiple algorithms (pow or pos) prevents this because if you have two algos and one of them stops because of the difficulty, the second algo can lower the difficulty of the other, super high one without having to find blocks with super high difficulty. Essentially the difficulty retarget now can't be stopped with kicking one algorithm's difficulty. And with multiple algos you can also set how many blocks can be found with a single algo in a row before at least one block if found on another algo.