Bulk data transfers by directly accessing a persistent and secured area on the data storage device, e.g., a disk drive having a magnetic storage medium, without relying on the system operating system to execute its read/write operations. For a disk drive, the Protected Area Run Time Interface Extension (PARTIES) technology is applied to create and organize a secured sub-area within a secured storage area. The secured sub-area is a data buffer to and from which large data file transfers can be made with data authenticity and confidentiality. Since this new secured sub-area is not organized and protected by the operating system, it is inherently protected from attack by viruses or Trojan horse software whose effectiveness depends on their ability to maliciously direct the operating system. In addition, the read/write operations bypass command payload limits while reducing data and command validation costs.