A newly published patent application filed by Sony outlines a content protection system that would use small RFID chips embedded on game discs to prevent used games from being played on its systems, all without requiring an online connection. Filed in September and still awaiting approval from the US Patent Office, the patent application for an "electronic content processing system, electronic content processing method, package of electronic content, and use permission apparatus" describes a system "that reliably restricts the use of electronic content dealt in the second-hand markets."

Used game sales continue to be a major concern for many big-name publishers and developers, who see the practice as a drain on the revenue they earn from selling new software. Sony's patent explicitly points out that suppressing the used game market will "[support] the redistribution of part of proceeds from sales of the electronic content to the developers."

The used-game blocking method described in the patent involves a "radiofrequency tag" and a type of programmable ROM chip that are paired with each game disc and can communicate wirelessly with the game system. The tag and chip can be used to store "unique information" about each console the game has been played on. Thus, when the game is used on a second system, the unique information stored on the disc can be compared to the information stored inside the new hardware, and in turn checked against "use permission" data stored on the EEPROM chip itself. As described in the patent, this "unique information" could be a system identifier or some sort of unique user ID that is somewhat portable between systems.

The patent describes users being asked to "pass the use permission tag over the RF reader/writer," suggesting some sort of near-field communication (NFC) area on the system itself that is used to launch this confirmation process. The patent also describes the RFID tag being used to decrypt content on the disc, which could provide a method for locking certain on-disc content to certain users who have unlocked or paid for the privilege. The system would theoretically also make game discs much harder to pirate, since illicit copiers would have to include correctly configured security chips in their copies, rather than using off the shelf media.

Of course, the fact that Sony has applied to patent this idea is a far cry from confirmation that this kind of protection system is in the works for the PlayStation 4. Even if it is, Sony could easily leave it to individual publishers to decide whether or not to implement it. In May, industry analyst Michael Pachter recounted a conversation with SCEA president Jack Tretton where the Sony executive said he was "totally opposed to blocking used games."

It was about this time last year that rumors started to swirl that Microsoft was planning to block used games from being playable on the next Xbox. In March, similar rumors popped up surrounding the PlayStation 4, codenamed "Orbis" in leaked documents.

At the time, we examined some potential technical methods for implementing this used-game blocking, including the kind of disc-linked solution being discussed in this patent. While this kind of resale-blocking technology would seemingly run afoul of the first sale doctrine codified into US law, legal experts seem unsure about whether that doctrine would be enough to overcome the end-user license agreements common to video game sales. After all, the practice of restricting game resale is already taking root through the wide adoption of digital distribution, which prevents players from reselling downloadable games in almost all cases.

Now that Sony's patent has proven that the company is thinking about whether it could block used game sales, the question from the company's point of view becomes whether or not it should. While a total technical ban on used game sales across an entire console would have an effect on the market for new games, it's far from clear what that effect would be. The availability of cheaper used games does discourage people from picking up new games (GameStop alone sells roughly $2 billion in used games each year), but the money or store credit players get from selling used games is usually plowed right back into buying more games, many of which are sold new. In a world in which all used video game sales were blocked through technical means, the new game market would quickly reach a new equilibrium of supply and demand for titles that are locked to a single system.

In the end, Sony's decision of whether or not to implement the idea outlined in this patent application will probably come down to the collective weight of two countervailing forces. On one side, there are the developers and publishers lobbying for tighter controls to protect their markets. On the other, there are players who might not be too keen on buying a system that can't play secondhand games (or on buying games that they'll never be able to resell).