Last year Walmart began experimenting with blockchain and looking in to how it could improve the retail giant's efficiency.  Teaming up with IBM, Walmart’s first test runs were using blockchain to track pork coming from China, and mangos coming from Mexico.

Today they took another big leap towards becoming a blockchain powered business - this time filing a patent of their own.

The abstract overview of the patent reads:

"A registration-based user-interface architecture includes a retail shopping facility operated on behalf of an enterprise having a plurality of physically-discrete items disposed therein that are offered for retail sale. A control circuit maintains a record (for example, in a blockchain ledger) of a particular customer's purchase of a particular one of these items and also provides an opportunity to that particular customer to resell that particular item via a sales platform operated on behalf of the enterprise. By one approach the control circuit is further configured to interface with the particular customer to register that customer's purchase of this particular item. That interface may be conducted, for example, via a point-of-sale interface, a browser-based interface, a mobile device app-based interface, and so forth. By one approach this registration must necessarily occur within a predetermined amount of time from when the customer purchases the item."

Basically, using blockchain when a package is delivered the actual delivery person would use a private key to release the funds for the item right there on the spot. Keep in mind this would be done through software and likely be as simple for the delivery person as pressing a button - the private key exchange would then be done with software behind the scenes.

Walmart is testing a new delivery service called "Deliv" that involves the delivery person being able to unlock your door, and actually come in and put away your groceries, they described what they're testing on their blog:

"I place an order on Walmart.com for several items, even groceries. When my order is ready, a Deliv driver will retrieve my items and bring them to my home. If no one answers the doorbell, he or she will have a one-time passcode that I’ve pre-authorized which will open my home’s smart lock. As the homeowner, I’m in control of the experience the entire time – the moment the Deliv driver rings my doorbell, I receive a smartphone notification that the delivery is occurring and, if I choose, I can watch the delivery take place in real-time. The Deliv associate will drop off my packages in my foyer and then carry my groceries to the kitchen, unload them in my fridge and leave. I’m watching the entire process from start to finish from my home security cameras through the August app. As I watch the Deliv associate exit my front door, I even receive confirmation that my door has automatically been locked."

This new patent is likely how the billing would be facilitated for this delivery service.