From:He would know. Wearable devices can give away your PIN number, according to research he and colleagues presented in June at the 11th annual Association for Computing Machinery Asia Conference on Computer and Communications Security (ASIACCS) in Xian, China. By combining smart watch sensor data with an algorithm to infer key entry sequences from even the smallest of hand movements, the team was able to crack private ATM PINs with 80 percent accuracy on the first try and more than 90 percent accuracy after three tries.
I have to admit, at the beginning, I thought this would be science fiction, says Wang. But it can actually be done. There are just so many sensors on these wearable devices. It provides sufficient information of your hand movements.
Your Smart Watch Can Steal Your ATM PIN - IEEE Spectrum