I can’t find the article, but didn’t another Nordic country, where they’re going cashless already find a flaw? Their communication infrastructure had some sort of disruption, I don’t think it was an attack, but a failure of something for like half a day. Because of that, merchant services were screwed. Few people could buy anything since few carried cash. Don’t get me wrong, I barely carry cash on me. I just have a b…
If your bank is local, as is your merchant's, you could design the payment network in such a way that, if your region is cut off from the rest of the Internet, local communication can still allow payment authorizations to go through.