Provided is a method of preventing digital content from being used despite the presence of copy control information. In the method, a security apparatus capable of restricting use of contents generates a nonce with respect to a storage device and stores the nonce in the storage device and a memory separated from the storage device when content is stored in the storage device; updates the nonces stored in the memory and storage device when movement of the content occurs; and permits use of the content only when the nonce of the storage device, which is stored in the memory, is equal to the nonce stored in the storage device if the content is requested for use, thereby preventing a disk cloning attack.