Abstract: A method for protecting at least one file on a memory device includes the steps of attaching the memory device to an origin computer, wherein a file is located on the origin computer and accessible through the attached memory device. The user then operates software resident on the memory device via the origin computer and designates the file to be transported to the memory device. The user selects a password and commands the device to encrypt the file. The file is compressed and encrypted, and subsequently saved on the device. The user disconnects the device and attaches it to another computer. By operating the deice software on another computer, the user selects the file and enters the password. The software decrypts the file and expands it. The file is saved to the memory device or the computer. The device may be detached again for further use.