Patent ID: 6223285
Filing Date: 2001-04-24
Classification: G11B,H04L,H04N

Abstract:
A system for transferring information, said system comprising:a source device for encoding an encryption mode identifier (EMI) code into an information packet and for transmitting said information packet over a communication interface, said source device comprising:a first encryption circuit for encrypting data of said information packet provided said EMI code indicates a first mode; anda second encryption circuit for encrypting said data of said information packet provided said EMI code indicates a second mode; anda sink device for receiving said information packet from said communication interface, said sink device comprising:an extractor circuit for extracting said EMI code from said information packet; anda first decryption circuit for decrypting said data of said information packet in response to said extractor circuit indicating that said EMI code is of said first mode; anda second decryption circuit for decrypting said data of said information packet in response to said extractor circuit indicating that said EMI code is of said second mode; andwherein said first mode is a copy prohibition mode indicating that said information packet is not to be reproduced by said sink device and wherein said second mode is a copy once inhibition mode indicating that said information packet is not to be reproduced more than once by said sink device; andwherein said first encryption circuit, said second encryption circuit, said first decryption circuit and said second decryption circuit are coupled to receive a same cipher key.