Bitcoin’s block chain has become well known for its use as a public ledger for digital currency transactions. By harnessing a decentralized network that is now more powerful than the top 500 supercomputers combined, it has removed the need for third parties like banks to verify online transactions, vastly reducing the costs of doing business. The extension of this technology has the potential to revolutionize the way people forms contracts, register domain names, and now, even prove ownership of intellectual property.

A copyright is a form of intellectual property that grants the creator of an original work exclusive rights to its use and distribution, usually for a limited time, with the intention of enabling the creator to receive compensation for their work. According to U.S. Copyright Office, a copyright is formed the moment a work is created and fixed in a tangible form that is perceptible either directly or with the aid of a machine or device.
For decades, struggling writers and musicians, looking to copyright their work on a budget, have misguidedly resorted to the Poor Man’s Copyright, where one sends a copy of their own work to themselves through the mail so as to have it postmarked. Because of the ease by which this copyright can be faked, for example, by mailing an unsealed envelope to oneself and placing the work inside thereafter, this method has rarely, if ever, been accepted as proof of copyright by any courts in the United States.  
For 5 mBTC (less than $1), Proof of Existence provides a method by which writers can demonstrate document ownership and proof that a document was authored at a particular time using the block chain technology. Although still in its initial stages, Manuel Aráoz, a Buenos Aires, Argentina-based developer, who built Proof of Existence as a decentralized method of verification, a kind of cryptographic notary service explained:
“As the block chain is a public database, it is a distributed sort of consensus, your document becomes certified in a distributed sort of way.”
Here’s how it works: After anonymously uploading a document and paying the fee, a hash of the document (or any other type of digital file) is generated, though the actual file is not stored online. This hash is a cryptographic digest of the file, which ensures the work satisfies the “fixed” requirement of a copyright, because even a small change in the original file input would lead to a great change in the hash output. When this transaction is mined into a block, the block timestamp becomes the document’s timestamp, resolving the date the copyright was established. So using the public and ledger-like nature of the block chain, a creator can offer proof of ownership should an issue of authorship or dating arise. 
The other option, of course, is to pay for a notary. While the Proof of Existence method has yet to be offered as evidence of a copyright in court, a favorable ruling in one case where the block chain certifies that something happen at particular time could be enough to set a precedent for future cases. So as Bitcoin awaits a sea change in consumers’ and businesses’ minds that will herald the “Internet of money” into its golden age, the potential of the block chain to serve as a record of fact, or just Poor Man’s Copyright 2.0, has yet to be determined.