Just reposting what i’ve posted on keybase some time ago, so that it doesn’t get lost.
let’s say amazon integrates grin. You have a cart with items in it and then click “checkout”. Now you have 2 different flows:
SRS:
- user copies the total amount of his cart and also copies amazon’s grin address to create step1 slatepack
- user enters the generated slatepack on the amazon page, amazon generates next slatepack
- user copies this new slatepack and finalizes the transaction
Here amazon doesn’t know if the user has signed the tx or if the transaction didn’t reach the chain etc.
User had to copy the amount, amazon’s grin address, create the first slatepack, copy next slatepack and finalize.
RSR:
- user enters his grin address (so that exchange can encrypt for him), amazon generates the new slatepack which the user copies
- user generates the next slatepack through the “pay” subcommand
- user pastes slatepack on the amazon page
Here amazon knows exactly the state of the transaction.
User had to paste his grin address, copy slatepack, pay to create the second slatepack and paste it
From my understand of early payment proofs, memo would need to be created in the first step of SRS (well at least that makes sense to me although it might be possible to push it to step 3 but it makes less sense), which means the user would also need to take care of the memo, instead of letting amazon automate this process - amazon has the digital cart data, so it can either populate the memo with it or generate hash of it and send you the receipt or smth. I might be wrong, but i don’t see real services being happy with the SRS flow integration