and is requested to contact the helpdesk in case of loss. From a
security point of view, it is possible to read the data stored on
the body weight scale with any other mobile phone running an
appropriate NFC reader application. However, reading out just
the single stored last measurement value from most of such measuring
devices is always possible via the display and as such no
security risk. To avoid, however, that a value would be uploaded
twice—either by the same or another user—we implemented
a filter mechanism based on the device’s serial number and a
unique session identifier for each measured value. In case of the
described prototype—where a blood pressure and ECG sensor
has been combined—it would be quite complex to read out the
data by an unauthorized person’s mobile phone due to the fact
that the data are streamed in real time and not stored to be read
afterward. Spying out or manipulating these data would require
an eavesdropping or MITM attack. This can be prevented in
future designs by using an encrypted link based on the concept
described earlier.