Apple has recently been awarded a patent related to the technology for Apple Watc. This technology is based on NFC for use with watch straps.
Apple has designed a watch strap with a built-in NFC chip to communicate with the Apple Watch. First of all if the user changes the watch strap, the watch face will also change to the same color theme as the strap. Another function that may be offered is that certain watch straps can continue to open special applications.
According to Patently Apple, this patent also allows the Apple Watch to warn users if a non-genuine watch strap is used. The same warning if the user uses a cheap lightning cable. Sources also state that the use of unofficial watch bands can also disable some specific functions forcing users to use only official watch bands.
For now this thing is just a patent. Not sure yet which Apple Watch models Apple will integrate. Let's wait together.