Why does the applet need unrestricted access to my system?

All SignLive! CC cloud suite applets interact with smart cards, which are connected through a card reader to your operating system.

The PC/SC service manages all card readers connected to your PC. Every application must talk to this service to get a communication channel to the card reader. Thus the applets needs your permission to contact the PC/SC service outside the JVM sandbox. That for the applet requires the permission for an unrestricted access to your system.