Verizon Communications, the largest telecommunications company in the US, is experimenting with blockchain technology.

Blockchain technology, which powers Bitcoin and other cryptocurrencies, depends on a distributed ledger that allows users to verify transactions without an intermediary.

Autonomous Research has called the technology a "game changer," and Goldman Sachs has said that the technology "has the potential to redefine transactions."

Blockchain has tons of applications that are being explored by banks, startups, exchanges, and corporations that want to get in on the action.

Business Insider obtained a copy of the US patent, filed on May 10, for a passcode blockchain that Verizon has apparently been working on for three years.

The patent relates to digital content — think an e-book or a digital-music or video file. Verizon declined to comment.

Here is a passage from the filing:

"The DRM (digital rights management) system may maintain a list of passcodes in a passcode blockchain. The passcode blockchain may store a sequence of passcodes associated with the particular digital content and may indicate a currently valid passcode. For example, a first passcode may be assigned to a first user and designated as the valid passcode. If the access rights are transferred to a second user, a second passcode may be obtained and added to the blockchain, provided to the second user, and designated as the valid passcode. Thus, the first passcode may no longer be considered valid. If the second user transfers the access rights to a third user, a third passcode may be obtained and added to the blockchain, provided to the third user, and designated as the valid passcode. Thus, the first and second passcodes may no longer be considered valid.

"Furthermore, the expiration date associated with the key may continue to be in effect with respect to the second user and/or any subsequent users. Thus, if access rights for a particular digital content are associated with a rental period, or a subscription period, users may continue to transfer the rights to other users during the rental period."

There is quite a bit of excitement about having digital rights on a blockchain-type system. It could allow for pay-per-usage, for example, while smart contracts — the contractual clauses that form part of a transaction — could provide automatic payment distributions, according to a Moody's Investors Service report.

A blockchain of digital rights for consumer products — music and news articles, among others — could ensure that artists or authors are paid immediately once a consumer reads an article or listens to a song, with funds proportionally distributed as per contractual clauses.

Given lower transaction costs on a blockchain, micro-payments through a blockchain would be more feasible, allowing for a pay-per-usage setup each time an article is read or a song is listened to.