Li-fi: an Internet through a light bulb

Imagine an office where every computer, mobile phone and tablet is connected to the Internet, not through an ethernet connection or via Wi-Fi, but just through the overhead lights.

That is the vision that Harald Haas lays out for me when he visits my office to demonstrate his LiFi technology.

Mr. Haas has been working on this at Edinburgh University for some years, and is now running a company called Pure LiFi to try and commercialise the technology. The university itself has invested in a LiFi R&D Center to try to kick-start an industry that might turn Edinburgh into a world centre for this technology.

Next week, Mr. Haas and a team which includes some of his former doctoral students will take their equipment to Mobile World Congress in Barcelona. So the demonstration in our office feels like quite a big deal — will it work and will it impress?

They set up two laptops on a table, one with a conventional connection to the Internet, linked to a piece of kit which is in turn connected to a conventional light fitting. The other computer has a bulky unit attached to it, effectively a light receiver. It’s by making the light flicker very rapidly that data is conveyed from one computer to the other. It’s a bit like Morse code, explains the professor, but in a very sophisticated way, achieving very high data rates.

And lo and behold!, it works, with the second laptop streaming a video which buffers and halts once I block off the light completely. Impressive then, but I have several questions about the practicality of getting LiFi adopted in the real world.

The clunky receiver unit looks a long way from being a finished product. The team admits there is much to do in this area, but with enough investment they believe they can miniaturise this process so that it will be a 1-square-centimetre device that can be fitted into any smartphone.

Why an alternative?

Even then, there is a more important question. Why do we need an alternative means of connecting to the Internet when Wi-Fi works so well? Wi-Fi is indeed a great success, says Mr. Haas, so much so that the radio spectrum is getting overcrowded. We have deployed so many wireless access points that they interfere with each other and slow down the actual data rates. We need other pipes, fatter pipes, and light is a big pipe for wireless connectivity.

Security benefits

He also maintains that there are security benefits. Light-generated Internet connections do not travel through walls, so cannot be intercepted like a Wi-Fi signal. The professor looks forward to a future where the much-hyped Internet of things becomes a reality; where there is wireless connectivity everywhere; where your fridge talks to your toaster. This provides the means to achieve that.

It is a beguiling vision but a lot more work needs to be done before we all start flicking a light switch to get connected. — The New York Times

iPhones, iPads vulnerable to hacking

A major flaw in Apple's iOS mobile operating system could allow hackers to intercept email and other communications that are meant to be encrypted, the company said.

If attackers have access to a user's network, such as by sharing the same unsecured wireless service offered by a restaurant, they could see or alter exchanges between the user and protected sites such as Gmail and Facebook, experts said.

"It's as bad as you could imagine, that's all I can say," said Johns Hopkins University cryptography professor Matthew Green.

Apple did not say when or how it learned about the flaw in the way iOS handles sessions in what are known as secure sockets layer or transport layer security, nor did it say whether the flaw was being exploited.

But a statement on its support website was blunt: The software "failed to validate the authenticity of the connection."

Apple released software patches and an update for the current version of iOS for iPhone 4 and later, 5th generation iPod touches, and iPad 2 and later.

Without the fix, a hacker could impersonate a protected site and sit in the middle as email or financial data goes between the user and the real site, Green said.

Apple did not reply to requests for comment. The flaw appears to be in the way that well-understood protocols were implemented, an embarrassing lapse for a company of Apple's stature and technical prowess.

The company was recently stung by leaked intelligence documents claiming that authorities had 100% success rate in breaking into iPhones.

Friday's announcement suggests that enterprising hackers could have had great success as well if they knew of the flaw.