Proposal for Automatic Difficulty Adjustment in Bitcoin: A Safety Net for Catastrophes

Hey Bitcoin community, I wanna throw out an idea to tackle a possible weak spot in the Bitcoin network, especially during tough times like global disasters or huge drops in hash rate. Picture this: what if there's a big drop in hash rate because of a global disaster? Think about it, like massive damage to infrastructure or hardware from something crazy like a nuclear war or a surprise solar storm. It could take ages, like months or even years, to get back to those hash rate levels. During that downtime, the network might just grind to a halt since no blocks would be getting mined until everything's back to normal. So, here's what I'm thinking: let’s put in an automatic difficulty adjustment system as a backup plan. If no valid block is found for a set period (like 48 hours), showing a serious hash rate drop from unexpected events, the network could tweak the difficulty level to something more manageable, similar to the adjustment after 2016 blocks. Now, I'm not a coder, so I can't figure out the tech stuff, but this emergency adjustment could help miners keep finding blocks at a decent rate, even when the hash rate takes a hit from sudden global events. Basically, it could make Bitcoin more resistant to doomsday scenarios! By tackling this possible vulnerability head-on, we can help keep the Bitcoin network stable and running, no matter what crazy challenges come our way.

Bitcoin Testnet has such a difficulty adjustment but it introduces a lot of quick blocks being mined simultaneously. For starters, this isn’t that big of a concern since a huge overnight hit to the hashrate would indicate something far more serious than just a climate event happening, perhaps a nuclear war. If that happens, I’m not sure if mining would continue happening since every country would either be annihilated or imposing martial law. Hence, I don’t think it is worth a hard fork. This also introduces the possibility of miners trying to game the system by intentionally mining periodically to ensure that they try to get as many low difficulty blocks as possible. Either of this would not be good to Bitcoin.

In such extreme scenario, i expect people would try to trade their money for physical goods which makes money no longer valuable. I'd rather see Bitcoin community accept necessity of increasing maximum block size rather than prepare for this kind of extreme scenario. Something more complex such as EDA (Emergency difficulty adjustment) which used by BCH would be better option.

Let's be realistic: in those scenarios, Bitcoin is the last thing on my mind. Without global network, you'll end up with separate Bitcoin chains: Chinese miners will mine their own blocks, European miners will use other blocks, and American miners will also have their own chain. Once global communications get restored, the longest chain will force a reorganisation on all other continents. Unless there's a manual intervention, for instance because the interests have become too big. In that case Bitcoin may Fork into different versions for each continent. If for some reason 99% of all hashrate gets destroyed, a manual intervention can adjust the algorithm with support of the community when needed. It's probably going to be gold, cigarettes and booze that's traded for food. Unless the other guy has a gun, then you lose.

EDA or their improved DAA are not well implemented and there are many drawbacks to those. It was demostrated that the implementation that BCH used wasn’t good enough for production and it’s only there because the hashrate is low enough to be influenced by swing miners. My understanding is that these difficulty adjustments with a moving window or a different algorithm like Kimoto Gravity Well has too many drawbacks and should only be considered if the hashrates swings rapidly frequently.

Yeah, i'm aware it has few major flaws (there are even few research about it) and hence why EDA was replaced with modified DAA instead. Although on other hand, is there any less worse algorithm which already tested on live network?

Not that I currently know of. Loads of altcoins has their own difficulty adjustment, DGW (Dark Gravity Wave) and Digishield are prominent ones, and AFAIK there were different tradeoffs as well. The algorithms are generally designed for specific goals and has different tradeoffs. It wouldn't be applicable to Bitcoin because we don't have huge fluctuations in hashrates. No such thing as less worse, because they are all not good enough if you've got a network that is stable.