A software entity on a host device attempting to access protected content in a secure memory device must be authenticated using a challenge/response authentication mechanism before the secure file system can be accessed. A file system filter determines whether requested content is protected. If the content is protected, the file system filter provides a challenge to the software entity and generates a file system filter response using the same challenge. The software entity must then send a software entity response using the challenge to the file system filter. If the file system filter determines that the software entity response matches the file system filter response, the software entity is allowed to access the protected content through a secure file system installed on the host device for the memory device.