an unauthorized user prevention device and method prevents unauthorized users from operating a devices such as firearms or other types of weapons , and can also prevent access as an anti - theft device for vehicles and doors to buildings . a users initially grips a handle containing pressure sensors , and a pressure signature profile is stored that is based on hand position of the user &# 39 ; s handgrip on the particular device as indicated by a change in pressure , pressure as a function of position on the particular device ; and pressure as a function of time . a comparator compiles the pressure signature profile and compares it with profiles is storage to determined whether a match exists . upon finding a match , a control unit releases an interlocking unit to enable the user to operate the device because he / she is authorized .