摘要 |
The present invention generally relates to systems and methods for ensuring proximity between a first, e.g., mobile device, such as a smart phone, and a second, e.g., immobile device, such as a multi-function device. The invention can include the second device displaying a pattern that represents a series of movements, which a user of the first device can mimic. The first device can thus prove that it and its user are in proximity to the second device. |