Date: 2020-10-28
Accepted
Network connection might be lost, when a meal is delivered to a fridge and a user comes to grab it. Then the fridge can't check data of the user online by card swapping, or in-app distance opening. But the fridge has a pin pad keyboard and still has quite sophisticated software and internal memory to process orders.
Update 2020-11-24:
We expect that every meal has its own unique id provided by the kitchen because some meals might be customized from the general catalog. Let's say lactose-free lasagna should be addressed to a specific user.
Then, at the purchase or production process, we can update the user's device with the meal's unique id and generate an access code based on meal ID.
Meals dispatched from a Ghost Kitchen, will have a special 6-8 digit code.
Now the user can grab the meal even if the smart-fridge is disconnected from the network at the moment of picking up the meal.
Pin codes for meals should be formed upfront and delivered early to devices (smart-fridge and user-device). Possibly, there might be a mechanism to update those codes with prepared meal delivery. The pin code should be quite long to lower the chance of a brute-force attack.
Bonus feature: it's easier to delegate meal grabbing to other people.
Risks: Someone can be so lucky that they can guess a pin code from a first attempt.
Arguments: 8th long digit codes are too long to type!