The Riksbank publishes the final report on the pilot project of the Swedish digital currency: focus on offline transactions.
On March 20th, the Riksbank, the Swedish Central Bank, released the fourth and final report on the e-krona pilot project. The report primarily focuses on analyzing the functionality of offline transactions.
Initially, the Riksbank had considered storing e-krona transaction information on users’ smartphones. However, it is now evaluating the implementation of an online wallet linked to a payment card. The card would serve as a payment tool and also record changes in the account balance even in offline mode.
The report analyzed four possible uses of e-krona offline:
- Funding and defunding money from the card;
- Offline payments on PoS devices via NFC;
- Offline e-krona transfers between two cards;
- Imposing limits on the balance and the number of transactions that can be made with a card.
Issues encountered
The Riksbank identified a problem with the synchronization of the balance offline after making a purchase. If the synchronization order after a series of transactions is incorrect, some wallets may display an incorrect or negative balance. To address this issue, an appropriate counter structure is needed to ensure the synchronization of offline payments in the correct order. The counters would also help prevent double spending attacks, where a user attempts to spend the same e-krona multiple times.
The Riksbank initiated the e-krona study in 2020. With the publication of the final report, the bank has expressed its intention to continue the research and development of the e-krona, in preparation for its potential introduction in the future.
