Instead of passwords, what if your tablet authenticated you each time you touched the screen?
Having to continually enter passwords isn’t so convenient, especially when you’re in a rush. With hopes of putting an end to login prompts, two researchers have developed an innovative way of authentication for pretty much any touchscreen device. The brainchild of Christian Holz and Marius Knaust (who you may recall from their earlier project Bodyprint), Bioamp is a smart strap that uses a biometric sensor and a low data rate transmitter to access and protect content on tablets.
“From each touch, the touchscreen senses the 2D input coordinates and at the same time obtains biometric features that identify the user. Our approach makes authentication during interaction transparent to the user, yet ensures secure interaction at all times,” the duo explains.
To test their concept on today’s gadgets, they first created a watch-like prototype. Bioamp is equipped with several electrodes that sense the impedance profile of a wearer’s wrist and then modulate a signal to the body through their skin. From there, the touchscreen obtains the biometric data, identifies the particular user, and continuously grants permission for each interaction.
As Hackaday notes, Bioamp’s electrodes couple a 50V 150kHz signal through a wearer’s finger to the touchscreen, which picks up both the finger’s location via capacitive sensing and the background signal that’s transmitted by the bracelet. This background signal is modulated on and off, relaying the biometric data.
“Since Bioamp senses contact with skin, it is sufficient to collect biometric values initially and then ensure that the same user is wearing the device during further use. When Bioamp detects that the user has taken off the band, it stops transmitting signals, waits for the band to be put on again, and repeats the biometric measurements for subsequent modulation,” the duo writes.
The researchers integrated their approach into a Surface 2 Pro running Windows 8.1 to demonstrate various use cases, which include payment for app store purchases, authentication for emails and notifications, as well as temporary access for sharing photos. Additionally, Bioamp supports logins that require more than one person to be present at a time. For example, two users would need to touch a single login tile simultaneously in order to unlock and open sensitive emails.
In terms of hardware, Bioamp is driven by a Blend Micro. This board features an ATmega32U4 MCU and an nRF8001 BLE chip, which handles the wireless data transmissions to the tablet to compensate for low touchscreen sampling rates. Meanwhile, power is supplied by a pair of 110mAh LiPo batteries.
While some may argue that there are limitations to the design, this idea of making touch interaction convenient and secure is pretty darn cool. You can see it in action below, and be sure to read all about it in their research paper here.