Just yesterday, CoinDesk reported eBay had filed two cryptocurrency-related patents with the US Patent and Trademark Office (USPTO) – the agency responsible for issuing patents and registering product and intellectual property trademarks.

In so doing, the online giant joined a slew of crypto and non-crypto companies which have also filed applications in an attempt to protect their products.

Often a topic of contention in the largely open-source bitcoin community, CoinDesk has rounded up some of the most high profile patent submissions revealed to date.

The best-funded company in the space filed two patent applications with the USPTO, one of which was for a digital currency mining circuitry. The patents were published by the agency on 15th October.

Submitted in April last year,the patents listed the inventors as Matthew Pauker, co-founder and chairman at 21 Inc; Nigel Drego, co-founder and chief architect; Veerbhan Kheterpal, president and co-founder; and Daniel Fir, co-founder.

"The present invention relates to mining of digital currencies such as cryptocurrencies," reads the filing, which goes on to state: "Mining circuitry and mining operations described herein may be used for any digital medium of exchange such as digital currencies, credits, rewards, or points."

Just last month, CoinDesk reported that San Francisco-based firm Coinbase had filed nine bitcoin patent applications with the USPTO.

Submitted in 17th March 2015, the filings included patent applications for various bitcoin products including a hot wallet, an instant exchange (launched in June), a bitcoin exchange and a bitcoin tipping button.

Coinbase's CEO Brian Armstrong took to Reddit to defend the company's decision to file for patent protection.

Speaking to CoinDesk at the time, he said:

Bank of America's patent application for a wire transfer system that would leverage cryptocurrency technology also made headlines last month.

Filed on 17th March by the US financial services giant, the filing sets out to garner protection for a system by which electronic funds could be transferred between customer accounts using blockchain technology as the payment rail.

Commenting on the purpose of the invention, its authors Thomas Edward Durbin and James Gregory Ronca wrote:

A patent application filed by BitGo caused concern among crypto enthusiasts and prominent industry figures, prompting bitcoin multisig wallet provider to address the issue on its blog:

The IPA – pioneered by Twitter in 2012 – BitGo added, stipulates that patents must be used for defensive purposes only, "meaning that patents awarded to employees cannot be used in offensive litigation without permission from the investors themselves".

Last year, global financial services giant MasterCard filed a patent to be able to incorporate bitcoin into the design of a proposed online shopping cart which would be rolled out on a global scale.

Speaking to CoinDesk at the time, a MasterCard representative said: "Every day, we look for ways to bring additional convenience to consumers when they shop. This application is just one example of that – exploring how to create flexibility in how a consumer would fund a shopping cart purchase."

The patent, MasterCard added, should not be perceived as support for bitcoin:

E-commerce giant Amazon was awarded a bitcoin-related cloud computing patent which outlined the use of digital currencies as payment for cloud computing services on Amazon Web Services (AWS) – the company's cloud-computing platform that, according to the company's CEO Jeff Bezos, is a $5bn business and growing fast.

As reported by CoinDesk at the time, Amazon's patent award came after the company publicly stated it was not interested in accepting digital currencies, despite its perceived competitor eBay hinting at integrating bitcoin payments.

Colorado-based remittance giant Western Union's patent award in April 2014, was subsequently followed by reports that suggested the company would have a claim to the exchange of alternative currencies.

Although it fails to mention bitcoin, the filing reads:

IBM filed a patent application to track the value of digital currencies in 2012.

Made public in 2013, IBM's application states:

"The ability to validate and authenticate digital tokens across the lifetime of any particular token will bolster trust and viability, allowing e-currencies to operate across disparate economic systems, fostering easier participating alongside sovereign currencies and non-standard currencies."

Paper filings image via Shutterstock.