Umm... since these signs are "legally binding" therefore these require atleast as much security as a user's passwords, no? So exactly what security measures are

Umm... since these signs are "legally binding" therefore these require atleast as much security as a user's passwords, no? So exactly what security measures are in place? With a typical text password, you don't even store it in plain-text, for fear of a compromised DB. So how are you protecting these signatures against a compromised DB?