Apple iPhone 5S fingerprint scanner gets plaudits in early reviews

San Francisco: The fingerprint reader on Apple Inc's top-end iPhone 5S received an early thumbs up for ease of use from two influential reviewers, helping dispel concerns about the scanning technology which has been notoriously unreliable in other cellphones.

Apple's scanner is seen as a first step toward realizing the full potential for biometrics in personal electronics, heightening security for applications like banking and shopping while doing away with multiple passwords.

"The best part is that it actually works - every single time, in my tests," wrote reviewer David Pogue of the New York Times.

"It's nothing like the balky, infuriating fingerprint-reader efforts of earlier cellphones. It's genuinely awesome; the haters can go jump off a pier."

The Wall Street Journal's Walt Mossberg was also enthusiastic, calling it simple and reliable. But he noted that the gadget would inexplicably prompt him for a password when swiping a finger to make purchases, which he blamed on a bug.

"I have come to like it and consider it a step forward, despite a few issues," he said of the overall device.

Re-tooled iOS7 mobile software, a better camera, a more useful voice-activated "Siri" personal digital assistant and a faster processor combined to make the iPhone 5S the best smartphone on the market, he added.

However, he argued that owners of the previous-generation iPhone 5 may not have a compelling reason to buy the latest device unless they specifically wanted the fingerprint reader.

Many industry analysts view the iPhone 5S and the cheaper 5C as being modest improvements on the previous generation, reviving fears that Apple's most innovative days may be behind it. They said the mere fact of a fingerprint scanner was unlikely by itself to make the gadget a sure win in a crowded market.

Apple has embedded the scanner into the iPhone's home button, while other mobile devices usually have it on the back, making it awkward for the user and increasing the number of failed attempts.

Archrival Samsung Electronics Co Ltd (005930.KS) and fellow South Korean electronics manufacturer LG Electronics Inc (066570.KS) have had problems incorporating the technology into finished products.

Touch ID: Inside the fingerprint scanner on Apple's iPhone 5s

Apple unveiled the new iPhone 5s and iPhone 5c at a special event held at its headquarters in Cupertino. While the iPhone 5c did not live up to its promise of being a 'low-cost iPhone', the iPhone 5s showed off some promising innovations, like the new Apple A7 chip and, perhaps the highlight of the event, a built-in fingerprint scanner called Touch ID.

Touch ID can be used to unlock the phone, by simply placing a finger on the Home button. It can also be used to confirm purchases made on the App Store, iBookstore or the iTunes Store.

You can scan and add multiple fingerprints (e.g. left and right thumbs, as well as index fingers), including those from multiple people (e.g. your wife or kids), and Touch ID will authenticate based on any of stored prints.

In case you are worried about privacy, Apple assures that fingerprints are encrypted and stored in a secure area inside the new A7 chip. Fingerprints are not accessible to any third-party apps, and nor are they sent to Apple's servers or backed onto iCloud.

So what's the technology behind Apple's latest innovation? The Touch ID capacitive sensor embedded in the Home button scans your finger at 500ppi resolution to get a high resolution image of your finger. The sensor embedded in the Home button is just 170 microns thin.

The new Home button is made out of sapphire crystal, one of the "clearest, hardest" materials out there. The Home button protects the fingerprint sensor and also acts as a lens to precisely beam your fingerprint to the scanner. The Home button is surrounded by a steel ring, that can detect touches and tell Touch ID to start scanning when a finger is placed.

The sensor uses advanced capacitive touch to take high-resolution image of the sub-epidermal layers of your skin. The resultant image is then analysed, and grouped into one of three fingerprint types: Arch, Loop or Whorl. It then analyses ridges and other details too small for the human eye to see, to come up with a match for one of the stored fingerprints.

Here's a video that gives a closer look at Touch ID.