Bitcoin Forum

Hi,

I was wondering something the other day about after rewards finish.

From what I understand, miners mine for tx fees, difficulty will drop as there will most likely be less miners or less powerful miners. Given this scenario.

theoretically if bitcoin block height was to reach the limit of 32bit int. 2,147,483,647 or even if it was 64bit int 9,223,372,036,854,775,808 block height (Not that I think it will actually ever get to this number) What could be done to prevent such measures. Would it even be a problem?

I imagine once the difficulty drops after rewards we will be back to quicker mining and finding blocks more rapidly. correct me if I am wrong.

Thanks for any theoretical answers :)

Assuming the average time of 10 minutes per block you only get 144 blocks per day, 1008 blocks per week and 52,416 per year respectively.

So in 10 years the height would only be 524 thousand and in 100 years only 5 million - so I don't think it matters if it is only a 32 bit number (we will have a hell of a long time to make any change if needed anyway).

That would make sense. Would Bitcoin always adjust it difficulty based on this 10 minutes then?

 I know there is an average time per block. I've just seen some blocks like when coins first start up first 100 are mined in minutes even though it has a 10 minute block time. I guess in that case it would depend how difficulty adjusts or how bitcoin adjusts its difficulty.

Yes - the difficulty adjustments are made to keep the average time at 10 minutes (but those adjustments are only made every 2016 blocks).

Even if on average the blocks were found a little quicker (due to a constantly increasing hash rate) you wouldn't expect the number of blocks being created to be greater than say double what the 10 minute average would predict (so still no issue in regards to a 32 bit number being used for height).

Thanks for your solid answers CIYAM :)