Apple has been filed a US patent application on an embedded SIM capable of switching between mobile network operators under command from Cupertino, assuming the operators comply.

The patent places an embedded SIM within the secure element which one would expect to see managing electronic payments, which is why it was spotted by NFC World. Its editor, Sarah Clark, realised the significance of the patent and how it validates last year's rumours that Apple was planning a cross-network SIM-less handset.

We discussed that idea almost exactly a year ago, coincidentally on the very date the patent was filed. We pointed out that in Europe the legally mandated GSM standard requires a removable SIM, and that Apple would have to get the standard changed before would be allowed to sell such a device. That change is now in process, but we didn't expect Apple to patent the idea too.

The patent describes an embedded module pre-loaded with valid credentials for all the appropriate network operators. The user would then select a network operator through iTunes and those credentials would be presented to the air network.

GSM network security is based on a secret which is shared between the SIM and the network's Authentication Centre. That secret is never transmitted, and as each SIM has a different secret, the fact that a few researchers have managed to read the keys of a few SIMs (using electronic microscopes and/or analysis of power-consumption) doesn’t invalidate the whole system. But putting the secrets into the phone instead means pre-programming them during manufacture, and sharing them with the manufacturer.

The patent suggests that the requirement for a removable SIM "make[s] the devices bulky and add[s] cost", and that having to slot a SIM into a phone reduces the options for "when the user is not able to easily obtain a SIM card". But in reality, this is about ownership of the customer and control of the relationship.

The SIM in a mobile phone is owned and managed by the network operator, and many people, particularly younger people, identify more with their SIM (which stays with them) than their handsets (which are transitory). That's very annoying to Apple, which sees network operators as an irritating speed bump between them and their customers.

Apple will need to play nicely for a while though. It still needs to get the embedded SIM though the GSMA, and into the GSM standard, before it will be legal to deploy in Europe (all cellular networks in Europe are required to conform to the GSM standard).

Apple will also need to get the network operators to hand over the secrets for embedding into iPhones. Our first thought is that this could never happen, network operators would never hand over the keys to their most-valuable possession (the customer), but operators have proved surprisingly spineless before and at least there's a patent in place so Apple will be the only company allowed to relieve them of the last thing of value they own. ®