2020 vision: Digital wallets will empty faster

Anthropologists know there are three things most of us now carry with us wherever we go: our keys, our wallets and our cellphones. Digital wallets could fold the last two into a single item - and perhaps eradicate cash altogether. Could it change how we spend too?

A digital wallet is a chip inside your phone that uses wireless "near-field communications" technology. Pre-charged with money or able to request a sum from your bank later, the wallet hands over payment when you swipe it over a retailer's card reader. Cellphone users in Japan have used them for years, but the technology is only now emerging in a big way elsewhere. It is set to transform the payment industry, because mobile and web companies such as Apple, Nokia and Google are keen to rub shoulders with incumbents like Visa.

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Smart software cracks sound-based CAPTCHA security

                                                             TECHNOLOGY

Efforts to make the web more accessible have unwittingly made it less secure, according to computer scientists who have developed software to crack the audio CAPTCHAs used by websites as part of their sign-up process.

You're probably familiar with traditional CAPTCHAs, the obscured words used to verify that a new user is a person rather than a bot, but the image-based security measure is difficult for visually impaired people to use. To help such users websites also offer audio CAPTCHAs, in which a computerised voice reads out letters or digits distorted by noise, but their security hadn't been as extensively studied as the visual versions.

Now, researchers have used software called Decaptcha to crack commercial audio CAPTCHAsused by eBay, Microsoft, Yahoo and others, with success rates from 41 to 89 per cent. The system known as reCAPTCHA - developed by the original inventors of the CAPTCHA and now owned by Google - was more resilient to attack, with only 1.5 per cent of CAPTCHAs broken. Even such a low success rate renders audio CAPTCHAs useless, as an attacker in control of a large botnet of infected computers can easily afford to make 100 attempts for every successfully created account.

Decaptcha uses a number of audio-processing techniques to remove noise and identify the individual digits in an audio CAPTCHA. The software has to be trained for 20 minutes on each type of CAPTCHA and can then solve tens of CAPTCHAs per minute on an ordinary desktop computer.

The researchers say their techniques leave most modern audio CAPTCHAs unusable, and alternatives must be developed. Decaptcha struggles only with CAPTCHAs that include semantic noise, which are sounds that share characteristics with spoken digits such as music or vocal tracks. For example, reCAPTCHA uses background conversations to obscure the digits, making it hard for the software to pick them out.

Humans can also find these CAPTCHAs difficult to understand, however, which means reCAPTCHA has a high failure rate. The researchers suggest using music rather than vocal tracks could create CAPTCHAs that are still hard for Decaptcha but easier for humans, because we can tune in to the correct sounds. They presented their work yesterday at the IEEE Symposium on Security and Privacy in Oakland, California

Robo-Jeeves finds and folds your crumpled shirts

                                                   

SIMPLE as they seem, many routine domestic chores are still a big problem for robots. Fetching a beer from the fridge may be within a robot's grasp, but ask it to clear up a messy bedroom and it will be stumped. To a robot, a crumpled pair of trousers can look much like a discarded T-shirt, and it will struggle to tell a fluffy slipper from a sleeping cat.

The International Conference on Robotics and Automation in Shanghai, China, last week heard how some of these problems are being tackled. Pieter Abbeel and colleagues at the University of California, Berkeley, for example, have devised software routines capable of recognising items of clothing even when they are "crudely spread out" on a flat surface such as a bed. The software runs on a commercial robot called PR2, made by Willow Garage in Menlo Park, California.

To identify a mystery garment, the robot first holds it up using one of its two grippers. This allows it to estimate the garment's length, by using its twin cameras to detect its lowest point. Next, the robot holds the garment with both grippers and records its outline as well as distinguishing features that may correspond to a collar or buttons.

The software then applies a statistical technique called principal component analysis (PCA) to generate a digital signature - a list of parameters that characterise an item according to whether it has sleeves or buttons, for example. By comparing this against a database of common clothes, the robot can decide what kind of garment it is holding.

Having made its decision, the robot then folds the item according to the appropriate entry in a stored table of instructions. In tests run by the researchers, the PCA-based technique proved around 90 per cent accurate at identifying garments.

At Cornell University in Ithaca, New York, a team led by Ashutosh Saxena has programmed a robot to find shoes scattered about the home. The software is primed with data on the form and other characteristics of shoes, and the team says it can be adapted to find other household objects.

One of the software's tricks is to pay special attention to places where shoes might be likely to end up: under a bed, beneath a coffee table or next to a kitchen cabinet, for example. The team has also developed software that allows robots to grasp household objects without damaging them.

In the same week as the Shanghai meeting, iRobot of Bedford, Massachusetts, the company which makes the Roomba robot vacuum cleaner, was drumming up support for its new domestic robot at a Google developer conference in San Francisco. Named Ava, the robot has an Android or iPad tablet as its "head", and the company is encouraging software developers to create new apps for it, much as they would for a smartphone.

Kerstin Dautenhahn, a roboticist at the University of Hertfordshire, UK, welcomes the fact that robots are moving beyond being able to simply dance or run, and are being programmed to perform what at first sight seem mundane tasks. "These 'little' tasks are in fact very valid challenges that are big problems for machines," she says. "It's time they were focused on."