The present invention relates to a method for ensuring the security of an open platform. Specifically, the present invention pertains to a method of using a validation program, itself highly secure, to evaluate and securely flag files in software to be loaded and used on palmtop computing devices. The method prevents the infiltration and unauthorized installation of viruses, Trojans, and other known methods of compromising security in an open-platform system. Control of access to the operating system and the operation of applications and macros in a palmtop device is therefore maintained in the user.