qr-codes
Clients running on a graphic calculator
solar powered fpga miners
community networks
magneto optical storage
mobile datacenters
biofuel generators
carrier-less modulated light network technology
pick a few
if any technology would survive such a disaster it's gonna be bitcoin.
All this technology... none of it is proven to last as well as a physical book does. Think about the earliest computers from the 1930s... Even though that was only 60 years ago there are now hardly any working ones, and even fewer people who know how to use them. Compare that to books: Libraries and museums have books that are literally
centuries old, and everyone on the planet would know how to use them without special training.
As for security, to prevent copying you would obviously need a secure or secret location to stash them. I am thinking of a set of volumes, like encyclopaedia brittanica but with the blockchain as the content. Maybe you could also encrypt the text so its not obvious what it is. Anyway the advantage of seperate volumes is that way for most days you would only need to use the last volume and the rest could stay safe at home.
Well, yes bitcoin depends on computers and there is nothing we can do about it.
But it depends on how severe you scale a hypothetical SHTF scenario. My proposal (i think) would even work in a madmax style thing. If you go even further (goosebumps) you reach a point where you would ask yourself if man would even survive it. And even most dystopic stories do not go this far... at least I can't come up with something.
If there would be no chance of producing working electronics at any date bitcoin would die out. But this depends on the level of sophistication technology would recover to. Blockchains can be saved with various techniques and can be recovered by electron microscopy from almost any data carrier. Vacuum chambers are relatively easy to construct and can be used to bootstrap almost any hightech industry.
Saving blockchains in a low density format wouldn't be feasible imo.