The U.S. Postal Service is eyeing blockchain as part of a system for establishing digital trust, newly published patent documents indicate.

The "Methods and Systems for Digital Trust Architecture" patent application was published on March 22, having been initially filed last September. According to the application, "it is apparent that the tools that provide trust to the users are lacking in their ability to adequately provide a desired level of security," citing concerns like transaction tampering and insecure messaging, among others.

"There are many excellent reasons for online interactions to continue as they have been. However, in a multi-party, open source environment, there is also a need for a secure, trusted, and enforceable online environment, to enable greater trust and therefore expansion of offerings online," the application goes on to note.

The system outlined in the Postal Service's application includes several elements, including one dedicated to email and another that provisions public and private keys for the user. It notably also calls for a blockchain component that "may be configured to receive records from the user and add the records to a blockchain."

According to the application, some of these parts could work in tandem, including the bridging of the blockchain and email segments.

"In some aspects, the user email component is further configured to receive input indicating whether information indicating the transmission of the encrypted email body data is to be stored in a blockchain and store the information in a blockchain in response to the input," the application explains.

The Postal Service's application also highlights the use of a "special digital token," though it's not clear whether this refers to any kind of scarce form of data that would exist on the aforementioned blockchain. Per the text, "the token is used to create a record for the user for inclusion in a blockchain."

"The block chaining of a special digital token provides evidence that a specific transaction occurred, and specifically who was involved," it later explains.

The filing is a notable one, given that in 2016, a report from the Postal Service suggested that the mail carrier could move to create its own cryptocurrency as well as use the tech for supply chain applications, among other areas.

Mailboxes image via Shutterstock