Patent ID: 7146501
Filing Date: 2006-12-05
Classification: G11B,H04L

Abstract:
1. An encrypting apparatus using an encryption key contained in an electronic watermark, said apparatus comprising: generating means for generating a first electronic watermark which contains a first encryption key; electronic watermark inserting means for inserting said first electronic watermark containing said first encryption key into a first portion of data; and encrypting means for encrypting a second portion of said data with said first encryption key, wherein said electronic watermark generating means generates an n-th electronic watermark which contains an n-th encryption key; where n is an integer larger than one, said electronic watermark inserting means inserts said n-th electronic watermark into n-th portion of said data before said encrypting means encrypts said n-th portion with an (n−1)-th encryption key, and said encrypting means encrypts an (n+1)-th portion of said data with said n-th encryption key.