A new patent filing finds retail giant Walmart seeking to utilize blockchain technology to perfect a smarter package delivery tracking system.

In an application released by the U.S. Patent and Trademark Office (USPTO) on Thursday, Walmart describes a “smart package” that would include a device which would record information on a blockchain regarding the contents of the package, its environmental conditions, its location and more. It also suggests that its smart package could be used in tandem with other emerging technologies including “autonomous vehicles,” such as drones.

The patent was first submitted in August of 2017, and notably builds on a filing Walmart submitted for a blockchain-based drone package delivery tracking system last year.

Walmart explains in the filing that online shopping has created shipping challenges for retailers, particularly with regard to perishable products requiring temperature control, thus necessitating further innovation.

Walmart writes in the application:

“These online customers many times seek to purchase items that may require a controlled environment and further seek to have greater security in the shipping packaging that the items are shipped in.”

The application states that the blockchain component will be encrypted into the device, and will have “key addresses along the chain of [the package’s] custody, including hashing with a seller private key address, a courier private key address and a buyer private key address.”

In addition to its delivery drone aspirations, Walmart has sought to apply blockchain technology to other areas of its business.

Last year, it joined Kroger, Nestle and other food industry firms in a partnership with IBM to use the blockchain to improve food traceability. It backed a similar effort in China with JD.com in December.

Walmart storefront image via Shutterstock