Devices equipped with accelerometer sensors such as today's mobile devices
can make use of motion to exchange information. A typical example for shared
motion is shaking of two devices which are held together in one hand. Deriving
a shared secret (key) from shared motion, e.g. for device pairing, is an
obvious application for this. Only the keys need to be exchanged between the
peers and neither the motion data nor the features extracted from it. This
makes the pairing fast and easy. For this, each device generates an information
signal (key) independently of each other and, in order to pair, they should be
identical. The key is essentially derived by quantizing certain well
discriminative features extracted from the accelerometer data after an implicit
synchronization. In this paper, we aim at finding a small set of effective
features which enable a significantly simpler quantization procedure than the
prior art. Our tentative results with authentic accelerometer data show that
this is possible with a competent accuracy (76%) and key strength (entropy
approximately 15 bits).Comment: The paper is accepted to the 13th IEEE International Conference on
Pervasive Intelligence and Computing (PIComp-2015