Lisa LCD
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12
Protecting device and content
12.1
Locking the hardware keys on the Lisa
In a typical in-store application, you do not want unauthorized personnel to play around with the device
by changing the station or switching the device on and off. To restrict these unwanted actions, Streamit’s
Lisa LCD devices feature a keylock option.The Lisa keylock option protects the settings and operation of
your device from being altered from other individuals by locking the keypad.
If the keylock is on and someone wants to use the keypad of the Lisa, just press any of the buttons. The
Lisa will ask to enter the (numeric) PIN code. Once the right PIN is entered (using the numbered preset
buttons 1-5), the keypad is unlocked temporarily so the desired changes can be made. If no buttons are
pressed for 10 seconds, the keypad will automatically lock again.
The keypad-lock (keylock) can be enabled or disabled from the setup menu of the device, or by using
the
. In case you forget the PIN code, you can always use the master PIN which
is “1242”. It is also possible to use
to overwrite a PIN or disable the keylock.
12.2
Card track encryption
When you use the Lisa as a standalone player, the audio files need to be copied on the (micro) SD
memory card to be used with the device. When you copy audio files directly onto the card, anyone can
copy and later play them on their own system. The problem increases when “Store and Forward” is used.
For such an application it is required that files are placed on a web server and downloaded by the device.
Rather than trying to prevent copying the content, the approach to address this issue with the Lisa is to
encrypt the content and make it unplayable on other devices than the Lisa.
An encryption system using Streamit’s encryption technique is depicted in the figure below. The main
idea is simple; you use a “key” to encrypt your audio files. This is called the Encryption key and is
randomly generated using the
Streamit Card and Scheduler Toolkit
. The output (encrypted) files cannot
be played with conventional audio players.
The only way to play these files is with a Lisa device which contains the encryption key on-board, loaded
via the