Quote:The potential for digital-home assistants like Amazon Alexa to infringe on user privacy by making and saving voice recordings of them is already widely known. Now researchers have discovered that the devices also may be able to “hear” and record what people are typing on nearby smartphones, even amid background noise.
 
The microphones on digital assistants are sensitive enough that they can record the taps people make on a mobile device when sitting up to a foot and a half away, according to a team of researchers from the University of Cambridge. The researchers constructed an attack in which they used this capability to identify PINs and text typed into a smartphone.
 
“Given just 10 guesses, five-digit PINs can be found up to 15 percent of the time, and text can be reconstructed with 50 percent accuracy,” the team–Almos Zarandy, Ilia Shumailov and Ross Anderson—wrote in a paper published online, “Hey Alex, What Did I Just Type” [PDF].
 
The same group of researchers already had discovered ways that various forms of technology can potentially violate user privacy by engaging in what they call “acoustic snooping.” Last year, they published research on how a smartphone app has the ability record the sound from its microphones and figure out from that what someone has typed, giving it the potential to steal PINs and passwords.
 
The new research also builds on previous research that found that voice assistants could record the typing of keys on a computer to determine someone’s input, Anderson wrote in a blog post.