Patent ID: 7954162

Claim:
A data distribution system comprising: a data providing means for adding to content data first control information for controlling copying and display of said content data and for encrypting said content data having said added first control information to provide first encrypted data, a data transmitting means receiving said first encrypted data, for adding to said received first encrypted data second control information for further controlling copying and display of said content data and for encrypting said first encrypted data having said added second control information to provide second encrypted data and transmitting said second encrypted data, and a data receiving means for receiving said transmitted second encrypted data, decrypting said second encrypted data to recover said second control information and said first encrypted data, decrypting said first encrypted data to recover said content data, detecting said first control information from the decrypted first encrypted data, and determining whether said content data is output in further encrypted format based on at least one of the recovered second control information and the detected first control information.