In-store payments using Bitcoin

The possibility of in-store payments would further increase the potential usefulness of cryptocurrencies. However, this would require much faster transaction verification than current solutions provide (one hour for Bitcoin) since customers are likely not prepared to wait a very long time for their purchase to be accepted by a store. We propose a solution for enabling in-store payments with waiting times in the order of a few seconds, which is still compatible with the current Bitcoin protocol. The idea is based on a payment card in combination with a protocol for ensuring that losing a card does not mean losing the money on it. We analyse the required transaction verification delay and also the potentially added risks that the solution brings compared to current systems.Funding agencies: Research Centre on Resilient Information and Control Systems (RICS) - Swedish civil contingencies agency (MSB)</p

Analys av ett Bitcoinbetalkort : Design av ett nytt betalsystem som använder Bitcoin

This thesis introduces a debit card based payment system that aims to provide fast in-store payments using Bitcoin. The system introduces physical constraints to Bitcoin payments to enable stores to accept payments before they are in a block.The proposed system was tested in a proof of concept model to estimate the time itwould take to pay with the system on the real Bitcoin network. A security analysis was performed to validate system security and to point out potential problems. The security analysis was done by interviewing five experts from different organizations to receive different views on the system. The analysis of the system indicated that it could potentially be fast enough to be used in stores, however security problems exist and need to be considered