Patent ID: 6338139
Filing Date: 2002-01-08
Classification: G11B,H04N

Abstract:
An information reproducing apparatus for reproducing information from an information recording medium, comprising:first output means for outputting identification information to authentication objects, which are other than the information reproducing apparatus; first reception means for receiving a first challenge key which the authentication objects output in response to the first output means, and which is obfuscated in accordance with the identification information; second output means for outputting a first obfuscation key obfuscated based on the first challenge key received by the first reception means, and a second challenge key generated based on the identification information, said first obfuscation key and said second challenge key being supplied to the authentication objects; second reception means for receiving a second obfuscation key which the authentication objects output in response to the second output means and which is obfuscated in accordance with a third obfuscation key; generation means for generating a common key based on the first obfuscation key and the second obfuscation key, which is received from the second reception means and which is decoded in accordance with the second challenge key; and processing means for outputting information obfuscated in accordance with the common key generated by the generation means and supplying the information to the authentication objects, and for decoding the information from the authentication objects in accordance with the common key.