Patent ID: 7640436

Claim:
An encryption device, comprising: a content-key storage section adapted to store content-keys; a content-key generation section adapted to generate a content-key used for encrypting a content based on random numbers and store the generated content-key in the content-key storage section; a determination section adapted to determine whether or not a value of the content-key storage section in an initial state and a current value of the content-key storage section are different; and an operation section, the operation section including: a first encrypting section adapted to encrypt the content-key used for encrypting a content so as to obtain an encrypted content-key and output the encrypted content-key to outside of the encryption device, and a second encrypting section adapted to, when a content is input to the operation section and the determination section determines that the value of the content-key storage section in the initial state and the current value of the content-key storage section are different, encrypt the content using the current value of the content-key storage section as a content-key so as to obtain a second output data and output the second output data to outside of the encryption device, wherein the determination section comprises a register for storing a value of the content-key storage section at the time that said register receives a Power On Reset (POR) signal, and wherein the POR signal is a signal which pulses only once immediately after power-on or immediately after reset so that the content-key storage section is in the initial state immediately after a corresponding power-on or reset of the encryption device.