The first part of your question at least is an electrical and physics issue. The rambling about digital currency doesn't make much sense, doesn't actually ask a question, and isn't about electrical engineering. This is why I am going to delete it.

I think this is more related to astronomy than EE. Although somewhat on-topic here, the question would probably have been more at home at https://physics.codidact.com/. Like for example, is it feasible that some really big comet passing close to earth has a wildly different potential and then cause something similar? Questions like that are also fine at https://scientific-speculation.codidact.com/

Olin, not the so called deletion (as we have history) by moderator makes me feel bad as the naming of what I wrote as "rambling"; I personally do find the importance of brining this up because we all live in money-based economies; if the question, in its formal entirety is better fit to Scientific Speculation so I would gladly have it migrated (along with your answer) to there.

It is rambling in the sense that its not related to EE. Asking about characteristics of EMP is reasonable. Theory of electricity can be applied to the answer. It might be reasonable to ask how specific devices are effected by EMP, like computers. We don't care what those computers are running, though. You could just as well have asked about all your pictures getting corrupted. There is no electrical difference between that and digital currency data, or any other data, getting corrupted.

@JohnDoea There's several separate questions here: is it electrically possible to have some manner of global EMP event - that question could be asked either here or on the Physics site. If it's related to power grids etc, then here. If it's related to astronomy or nature forces, then the physics site. Then a question "what could cause a global EMP event" would be suitable for Scientific Speculation but not here. ->

And then finally a question along the lines of "what would happen if all digital currency gets destroyed" might also be suitable for Scientific Speculation. Now, if you are looking for a debate about why digital currency is bad, then none of these sites are suitable, since this is a Q&A platform.

Just a note: I meant to at least temporarily not be able to use something (digital currency as the only currency, in my theoretical case here), not to data corruptions / changes.

It really should be obvious that discussion of "temporarily not be able to use something" (like digital currency) has nothing to do with electrical engineering, and is therefore off topic here.

Olin, this is obvious for me, I wrote what I wrote just one comment above for the record.

Can there be a global EMP disaster - I'm sure there could be one day

I'm all for pulling SE information off a for-profit-company's services (and I've learned a heck of lot on EE SE), but this post kind of proves the difficulties in moderation and the needs to include folks. I found EE SE super dogmatic; "don't discuss design"/"design comments too much, you are banished to the chatroom no one uses" vs. "show us your schematic so we can fix your design" -- downvotes all the way.