File system control filter can control the file activities, which you can intercept the file system call, modify its content before or after the request goes down to the file system, allow/deny/cancel its execution based on the filter rule. You can fully control file open/create/overwrite, read/write, query/set file attribute/size/time security information, rename/delete, directory browsing these Io requests. With file system control filter you can developer these kinds of software: ?Create your Data protection Software. Block accessing your data based on your security policy, prevent data modification without pemission. ? Create your own encryption software via encrypt the write data and decrypt the read data. ? Create your own custom security policies to control the file access. ? Hide or replace the files in the directory. You can modify the directory buffer to hide some files or change file name.