Remember those strange inline headphone-cable controls on the new iPod shuffle? Well, it seems there's more to the peculiar beasties than meets the eye.

According to various sources reporting over the weekend, it seems the new shuffle controls contain an Apple authentication chip that is required just to make them work.

Hardware DRM?

The hardware lock-in is being seen as the equivalent of DRM copy protection placed on digital music – something Apple has gone on record as disliking.

In other words, if third parties want to make headphones for the shuffle, they're going to have to pay Apple a 'tax' by shelling out for the authentication chips they need.

Looking bad

So far, it seems that non-shuffle 3G headphones with inline controls just don't work on the new player, which seems to verify the speculation. We'll bring you news if Apple decides to clarify the mystery chip.