Method of applying multiple pipes to assist digital copyright management in a USB storage device

A method of applying multiple pipes to assist digital copyright management in a USB storage device, which provides a host connecting to the USB storage device through a USB line for performing the digital copyright management, the method comprising the steps:

• (A) connecting the USB storage device with the host for sending a descriptor;
• (B) sending the descriptor from the USB storage device to the host on demand, wherein the descriptor describes features of a plurality of input and output pipes, thereby transmitting messages associated with the USB storage device's function and capability to the host;
• (C) selecting mass storage interfaces by the host in accordance with the messages;
• (D) using random variables as coding parameter to produce coded password when the host requires accessing digital signature or private key, and selecting a non-1st Bulk output pipe to send the coded password to the USB storage device;
• (E) selecting a non-1st Bulk input pipe by the USB storage device for sending an acknowledgement of the coded password back to the host;
• and
• (F) using the random variables as coding parameter to encrypt data when the password is identified right by the host, and transmitting it through the non-1st Bulk output and input pipes.