File access system for efficiently accessing a file having encrypted data within a storage device

摘要

A file access system includes a file opening unit which opens a given file within an external storage device when a file opening request is issued by an application program. A determining unit determines whether a given file within the storage device has encrypted data when a reading request is issued by the application program. When the given file is determined as having the encrypted data, a reading unit receives a fixed length of the encrypted data from the given file and generates a block of decrypted data of the same size as the fixed length by performing a decryption wherein a position of the fixed length of the decrypted data is determined by a position indicated by the reading request.