Nintendo uses non-standard USB-C encryption to get rid of third-party accessories

It has been reported that Nintendo uses non-standard messages when identifying your device to prevent you from using third-party accessories.

How it should work

The USB standard has the word"Universal"in the abbreviation for a reason: it is used to connect keyboards, chargers, external SSDs and video cards, even medical endoscopes and other specialised equipment. It's convenient, but difficult to implement. For everything to work, you need small chips on both ends of the wire, essentially specialised computers that can tell each other what kind of device it is and what it can do. Even when you connect your phone to the charger, a modern charger tells the phone's controller how much current it can deliver, and the phone can ask the charger to lower the voltage if necessary (when it is almost fully charged or overheated). In this way, you can even connect two power banks to each other, and they will determine who will charge whom and with what current. That's why there were no universal connectors 30 years ago - chips were expensive.

When you connect any device via USB, first of all, they exchange technical information - what type of device is "in touch" and what are its technical characteristics. This "language" of communication is standardised and every device, regardless of where and when it was made, will understand all other devices. The world's very first USB mouse will work with a modern PC, and a USB flash drive can be safely inserted into the charging unit.

What Nintendo has done

Nintendo is known for trying to run its own ecosystem and not letting anyone else in. This happened with the Switch 2. Recently, it was reported that the Switch 2 does not connect to third-party docks because it requires a high voltage of 60 watts, which is not provided by third-party devices. Even in a proprietary docking station, but from a third-party power supply.

A journalist from The Verge connected a special signal interceptor to the console, which passed through and analysed the information exchanged between Switch 2 and its proprietary dock, and found completely atypical behaviour. Before starting to transmit the video signal, the devices sent each other more than 30 encoded messages that do not belong to USB standards. It is clear that if the console does not receive the expected response, it will not transmit the video signal.

Currently, the only third-party dock that works with Switch 2 is the Antank S3 Max. It doesn't transmit all the messages in exactly the same order and produces a slightly different voltage, but it transmits encrypted messages exactly the same as the original dock. All other reputable dock and accessory manufacturers are currently refusing to release their products for Switch 2. The thing is, there's no problem with simulating the responses of a branded dock. The problem is that Switch 2 is constantly updated and nothing will prevent Nintendo from updating the encryption algorithm at any time.

By the way, Antank's representative clarified that their dock supports firmware updates, so they are serious about catching up with Nintendo's cipher as long as it takes. It's not the gaming industry, it's Enigma versus Her Majesty's Intelligence.

Conclusions.

Traditionally, Nintendo is not going to comment on the motivation of its actions or the encryption algorithm. In addition to the theory about the power supply's power (which is nonsense, as modern power supplies already transmit this information via standard USB methods), there is also a theory that the Switch 2 dock has a cooling fan and third-party docks may not provide additional cooling. This could be resolved either by certification or in-house temperature control. Most likely, Nintendo is simply trying to avoid using third-party docks, probably not wanting to face possible out-of-warranty damage. Or it wants to avoid interception and illegal transmission of video signals from the console. Or to avoid connecting hacking devices for hacking. Or simply because this is the way of the samurai - we can only guess.