64 bit is no advantage on a device with less than 4 GB of non-upgradeable RAM.
Actually, there are several advantages. The most glaringly obvious is the fact that it has double the number of registers and that those registers double in size.
We are also changing over to ARM's redesigned version 8 of it's instruction set which adds several new types of instructions that previously didn't exist at all.
Also added is support for hardware based virtualization, as is seen on some Intel and AMD SKU's.
"The iPhone 5 is the most difficult device that Foxconn has ever assembled. To make it light and thin, the design is very complicated," said an anonymous company official to The Wall Street Journal. "It takes time to learn how to make this new device. Practice makes perfect. Our productivity has been improving day by day."
If you want a device you can sell for 99 bucks on contract it needs to be easier to make.
The security of the system is achieved by partitioning all of the SoC hardware and software resources so that they exist in one of two worlds - the Secure world for the security subsystem, and the Normal world for everything else. Hardware logic present in the TrustZone-enabled AMBA3 AXI bus fabric ensures that Normal world components do not access Secure world resources, enabling construction of a strong perimeter boundary between the two. A design that places the sensitive resources in the Secure world, and implements robust software running on the secure processor cores, can protect assets against many possible attacks, including those which are normally difficult to secure, such as passwords entered using a keyboard or touch-screen. By separating security sensitive peripherals through hardware, a designer can limit the number of sub-systems that need to go through security evaluation and therefore save costs when submitting a device for security certification.
So yes. ARM enables Apple to physically separate the operation of the biometric device and storage of encrypted biometric information in what Apple calls "secure enclave" storage where it is not available to the OS or to apps.
Google Glass and several similarly configured systems now in development suffer from another problem I learned about 30 years ago that arises from the basic asymmetry of their designs, in which the wearer views the display through only one eye. These systems all contain lenses that make the display appear to hover in space, farther away than it really is. That’s because the human eye can’t focus on something that’s only a couple of centimeters away, so an optical correction is needed. But what Google and other companies are doing—using fixed-focus lenses to make the display appear farther away—is not good.
Using lenses in this way forces one eye to remain focused at some set distance while the focus of the other eye shifts according to whatever the wearer is looking at, near or far. Doing this leads to severe eyestrain, which again can be harmful, especially to children.
Twitter's video-sharing app now blocks many searches for pornographic terms. Trying to search for the #porn hashtag (and other terms such as #sex, #boobs, and #booty) brings up no results at this time.
"What a wonder is USENET; such wholesale production of conjecture from such a trifling investment in fact." -- Carl S. Gutekunst