A small country uses a digital economy, meaning there is no cash used in daily transactions. All transactions are stored on a government's central database.

An EMP attack/blackout manages to take down the nations power grid and internet. Now the nation has no way to trade for goods and services.

How can citizens continue to trade during this this temporary problem? Whether a short-term blackout or a prolonged one lasting days?

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    $\begingroup$ Credit cards were used for decades offline, using mechanical devices called imprinters to copy the card details to preprinted autocopying forms. (That's why the card number and holder's name are embossed.) The current all-online chip-and-PIN system only became ubiquitous in Europe in the last decade, and as far as I understand in America one can still find old-style magnetic-strip-and-signature POS devices. And I know of no country where payment card transactions go to a "government" database; they normally go to a clearing-house database owned by the card-issuing banks. $\endgroup$
    – AlexP
    Mar 5, 2018 at 13:28
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    $\begingroup$ Here is a source for manual card imprinters. $\endgroup$
    – AlexP
    Mar 5, 2018 at 13:33
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    $\begingroup$ Seems like many of the same issues to provide resilience and recovery for, say, hurricanes and other non-EMP-related disasters. $\endgroup$
    – user535733
    Mar 5, 2018 at 13:48
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    $\begingroup$ There's a huge difference in effect between "an EMP attack" and "a blackout". A plain old blackout will not typically cause widespread physical and electrical damage to equipment, for example. $\endgroup$
    – user
    Mar 5, 2018 at 15:29
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    $\begingroup$ @AlexP Actually, it's the opposite. Chip and pin was originally designed to operate offline, that is, only communicating with the bank's central servers once every few transactions, or for high-value transactions. This was due to high European phone costs. The chip itself can provide a legally-binding cryptographically guaranteed authorization in place of the bank. A battery-operated chip-and-pin scheme would work fine for a while in this blackout. The US system is dependent on always contacting the bank, which is arguably more secure (e.g. a stolen card can be cancelled instantly). $\endgroup$
    – user71659
    Mar 6, 2018 at 2:05

4 Answers 4


If paper and pens still exist in this world, then physical invoices can be used as transaction records during the blackout.

An invoice is a document that records all info related to a transaction, such as the agreed price, the items sold, and when the payment needs to be made. Today, both electronic and physical invoices are used for transaction where payments are not immediate(source: I develop transaction software), such as large-scale purchases of bulk goods. They are typically issued by the seller to the buyer, so many businesses would already be familiar with generating invoices.

So, all that is needed to temporarily replace the electronic economy is a steady supply of paper and pens. The seller would write the goods being sold, the amounts, the prices, etc., and the buyer and seller would both sign/somehow mark the invoice in order to authenticate it. Two copies, one for the buyer and one for the seller, would likely be made. When the electronic systems come back online, these invoices would be used to ensure that the proper money transfers are made.

  • $\begingroup$ Awesome, besides signatures, what other options of authorization might there be during a blackout like this? $\endgroup$
    – mateos
    Mar 6, 2018 at 3:18
  • $\begingroup$ This paired with a government "credit" score would allow large purchases to still continue too. $\endgroup$
    – mateos
    Mar 6, 2018 at 3:28
  • $\begingroup$ @Albert: Fingerprints, stamps, rodents bred to be uniquely identifiable. Basically anything that could be used in court to prove the buyer or seller did actually agree to the invoice, or that can be possibly proved as a forgery if one side claims otherwise. $\endgroup$
    – Giter
    Mar 6, 2018 at 13:16


Having backups in protected sites will make sure the economy goes back to normal as fast as possible, just make sure you have a concise and detailed plan to restore the backups.


Well, things got really bad and the backups will take too long to get back online or they don't exist. Well, its time to bring back the chickens and start bartering.


If we are talking about a small nation, then their best bet would be to transition to a gift-economy or some similar model. Without anymore money on the country, then things and acts will have worth.

In the short term you will have people bartering for food, shelter, and manufactured goods. In the long term you will want to start a decentralized production grid where each village could sustain itself.


To expand on the answer by Albert:

Once upon a time, there was a mostly cash-based economy for the equivalent of $100 or less, and some sort of check for larger amounts. Then the "plastic money" became more and more prevalent -- first in the supermarket for the groceries, then at the bakery, finally at the hot dog stall for a quick snack.

But at first cash would simply become uncommon without being phased out. Small kids still get their pocket money in cash. One might give a coin to a beggar in the street. Things like that.

At some point, the government advises the citizens that a cashless economy is fine, but they should keep a little bit of cash in a safe place. Just as many governments advise their citizen to keep food and water for a few days at home, and candles and matches, and a battery-powered radio.

So sober, respectable citizens have an envelope with some mixed-denomination bills somewhere in their desks, and most still have a handful of coins somewhere.

When the blackout comes, those reserves are not nearly enough, any interesting stories arise.


Some of my ideas:

  • Invoicing, which is later reconciled once the system is up again
  • "Emergency" cash which is used only during those situations

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