发明名称 |
ENCRYPTION DEVICE, DECRYPTION DEVICE, DIGITAL WATERMARK INSERTING DEVICE, AND DIGITAL WATERMARK DETECTION DEVICE |
摘要 |
<P>PROBLEM TO BE SOLVED: To limit the reproduction of more secure digital contents by utilizing and combining digital watermark technology and encryption technology. <P>SOLUTION: In a period 1, an encryption device inserts a digital watermark W1 into data on the basis of algorithm A0 and encrypts the data by a cryptographic key K+W0 including the digital watermark W0. In a period 2, the encryption device inserts a digital watermark W2 into the data on the basis of algorithm A1 and encrypts the data by a cryptographic key K+W1 including a digital watermark W1. A decryption device decrypts the data by the cryptographic key K+W0 and detects the digital watermark W1 on the basis of algorithm 1/A0 in the period 1. In the period 2, the decryption device decrypts the data by the cryptographic key K+W1 including the digital watermark W1 and detects the digital watermark W2 on the basis of algorithm 1/A1 specified by the digital watermark W1. <P>COPYRIGHT: (C)2004,JPO |
申请公布号 |
JP2003304230(A) |
申请公布日期 |
2003.10.24 |
申请号 |
JP20020108237 |
申请日期 |
2002.04.10 |
申请人 |
NEC CORP |
发明人 |
TANAKA NOBUYUKI;WATANABE JUNYA |
分类号 |
G06T1/00;G09C1/00;G09C5/00;G11B20/10;H04L9/08;H04L9/14;H04N1/387;H04N7/08;H04N7/081;H04N7/167;H04N21/2389;H04N21/8358 |
主分类号 |
G06T1/00 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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