Economist.com
How to weave a cloak that makes you invisible

IN NORSE mythology, a magic cloak granted invisibility to Sigurd, a demi-god and skilled warrior with superhuman strength. Millennia later, a similar garment bestowed invisibility on Harry Potter, a schoolboy wizard. In the mortal (or Muggle) realm, engineers have for years tried with varying degrees of success to build such a device. This week a team of physicists and materials scientists announced it had devised a pattern for a potentially perfect invisibility cloak.

Light is an electromagnetic wave, with a longer wavelength than X-rays and ultraviolet, and a shorter wavelength than infra-red, microwaves and radio waves. All these electromagnetic waves are governed by four mathematical expressions established almost 150 years ago by James Clerk Maxwell. These equations represent one of the most elegant and concise ways to state the behaviour of electric and magnetic fields and how they interact with matter. However, because they are so concise, they also embody a high level of mathematical sophistication.

The team—Sir John Pendry of Imperial College London with David Schurig and David Smith of Duke University in North Carolina—used the equations to devise a way to cloak an object with a material that would deflect the rays that would have struck it, guide them around it and return them to their original trajectory. Maxwell's equations conserve certain properties—the magnetic field intensity, the electric displacement field and the Poynting vector that describes the electric flux of an electromagnetic field. These properties remain the same when others are altered. The team showed how these fields could be manipulated to flow around objects like a fluid, returning undisturbed to their original paths. The findings were published online this week by Science.

Light wave basics:

Light can be emitted, absorbed, transmitted or reflected by matter. Metamatter alters the shall we say 'traditional' ray paths!

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New Scientist Tech

A plane with no wires or mechanical connections between its engine, navigation system and onboard computers – only a wireless network – has been built and flown by engineers in Portugal.

The 3-metre-long uncrewed plane 'AIVA' relies entirely upon a Bluetooth wireless network to relay messages back and forth between critical systems – a technique dubbed 'fly-by-wireless'.

Tests flights carried out in Portugal have shown that the system works well. Cristina Santos, at Minho University in Portugal, who developed the plane, says the aim is primarily to reduce weight and power requirements. 'Also, if you do not have the cables then the system is much more flexible to changes,' she says.

Many modern planes already use electronic wires, instead of the mechanical links and cables found in older planes, to connect components. This is a lighter and more compact way to control these systems. Some planes, such as the Boeing 777 even use optical fibres, which can carry multiple signals through a single cable.

Radio jamming

Replacing wires with wireless radio links is a logical next step says Peter Mellor from the Centre for Software Reliability at City University in London, UK, who was not involved with the project. But he adds that it raises completely new safety issues.

Such wireless links could be susceptible to electromagnetic interference or even jamming, Mellor suggests. And it could be more difficult to build in back-up wireless connections, he says. "If you jam one link you would jam both," he warns.

But Santos and colleagues are working on this. She says Bluetooth is already fairly resistant to disruption as it is designed to guarantee a certain minimum data stream will always get through. "It has mechanisms for dealing with interference," she says.

In-car radio

Even so, Santos says the system would need extensive testing before she would be willing to ride in a fly-by-wireless plane. She also admits that stringent aviation regulations may mean the technology first appears in cars rather than planes.

"Cables are already a problem in cars," Santos says, because many manufacturers cram ever more electronic gadgetry into each new model.

She admits the idea of having no physical connections may seem scary at first but believes ultimately it will become an accepted way to control brakes and even steering mechanisms in road vehicles.

The findings were presented on Tuesday at the International Conference of Robotics and Autonomous Systems in Florida, US.

[CLB: Here we go. I've been watching the auto industry for signs of serious comittment to drive-by-wirelessm and to the lack or presence of a security strategy.]

Web Links

Cristina Santos

Peter Mellor, City University

International Conference of Robotics and Autonomous Systems

While searching for a picture of the AIVA unscuessfully, I came across this Swiss flying bot:

Swiss researchers have demonstrated a flying bot with an 31-inch wingspan and a weight of just 1 ounce, that can fly indoors, avoiding walls and other objects via its onboard cameras. The robot plane has gyroscopic stabilizers and a Bluetooth transmitter to send data back to a nearby computer.

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Security Watch: CNET reviews

Researchers at Harvard and the University of California at Berkeley found that the best fraudulent sites could still fool more than 90 percent of the survey's highly educated participants.
[Read more of this fabulous review]

Why Phishing Works

[(PDF) Excerpt of and from the paper's introduction]

INTRODUCTION

What makes a web site credible? This question has been addressed extensively by researchers in computer-human interaction. This paper examines a twist on this question: what makes a bogus website credible? In the last two years, Internet users have seen the rapid expansion of a scourge on the Internet: phishing, the practice of directing users to fraudulent web sites. This question raises fascinating questions for user interface designers, because both phishers and anti-phishers do battle in user interface space. Successful phishers must not only present a highcredibility web presence to their victims; they must create a presence that is so impressive that it causes the victim to fail to recognize security measures installed in web browsers.

Data suggest that some phishing attacks have convinced up to 5% of their recipients to provide sensitive information to spoofed websites [21]. About two million users gave information to spoofed websites resulting in direct losses of $1.2 billion for U.S. banks and card issuers in 2003 [20]. [Over 16,000 unique phishing attack websites were reported to the Anti-Phishing Working Group in November 2005 [2].]

If we hope to design web browsers, websites, and other tools to shield users from such attacks, we need to understand which attack strategies are successful, and what proportion of users they fool. However, the literature is sparse on this topic.

This paper addresses the question of why phishing works. We analyzed a set of phishing attacks and developed a set of hypotheses about how users are deceived. We tested these hypotheses in a usability study: we showed 22 participants 20 web sites and asked them to determine which ones were fraudulent, and why. Our key findings are:
• Good phishing websites fooled 90% of participants.
• Existing anti-phishing browsing cues are ineffective. 23% of participants in our study did not look at the address bar, status bar, or the security indicators.
• On average, our participant group made mistakes on our test set 40% of the time.
[Read the paper]

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