The current trend, asking if you want a receipt is of course "eco-friendly". However, this is just a workaround since there are no technical problems providing a digital receipt. That it has not happened is [probably] because the payment industry does not bother too much about things that mainly are between consumers and merchants.
Since "patent trolls" are always looking for new ways to screw people, I thought it might be appropriate publishing a disclosure of how such a system could possibly work. In fact, it is an integral part of the Saturn project (https://test.webpki.org/saturn) and can be tested by anybody having an Android device. Unlike commercial receipt systems, the devised scheme does not require any user registration; it is anonymous with respect to the payer.
The current trend, asking if you want a receipt is of course "eco-friendly". However, this is just a workaround since there are no technical problems providing a digital receipt. That it has not happened is [probably] because the payment industry does not bother too much about things that mainly are between consumers and merchants.
Since "patent trolls" are always looking for new ways to screw people, I thought it might be appropriate publishing a disclosure of how such a system could possibly work. In fact, it is an integral part of the Saturn project (https://test.webpki.org/saturn) and can be tested by anybody having an Android device. Unlike commercial receipt systems, the devised scheme does not require any user registration; it is anonymous with respect to the payer.
https://cyberphone.github.io/doc/defensive-publications/e-receipts.pdf