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