Patent ID: 7823213

Claim:
A recording apparatus for allowing copy restricted content including data that is set so as to be prohibited from, or restricted from, being copied to become reproducible in a time shifted manner, said recording apparatus comprising: a recording medium having a predetermined capacity for storing said copy restricted content; a recording device for recording data in said recording medium; wherein said recording device records said copy restricted content in said recording medium such that data of said copy restricted content recorded in said recording medium is reproducible in a time shifted manner; and said recording device allows data of said copy restricted content recorded in said recording medium to convert to a condition such that; reproduction of at least a portion of the copy restricted content recorded on the recording medium is impossible, said portion being converted to said condition after a predetermined period of time has elapsed since recording of said copy restricted content has started; wherein said recording device comprises: a time variation key generation device which generates a time variation key used for encryption or decryption of said data; an encryption device which encrypts said data of said copy restricted content; a key buffer which temporarily stores said time variation key which is used for encryption of said data of said copy restricted content; wherein said encryption device encrypts said data of said copy restricted content before said data is recorded in said recording medium; said recording device implements said condition by erasing said time variation keys corresponding to said data being in such a state that said predetermined period of time has elapsed since the time the recording of said copy restricted content has started.