A registry monitoring method particularly applicable to a system (100) in which protected data is transmitted to a recipient computer. The method comprises requesting a handle for a registry key to a calling process, requesting a registry key value for the handle, modifying and deleting keys and values of protected data locations, and obtaining security clearance to complete the requests by checking secured process lists and rejection lists. Also included are a registry monitoring system, a secured data transmission system including registry monitorings, a machine-readable medium comprising a program to monitor a registry (110), and a computer configured to monitor a registry (110).