发明名称 |
Key generating method, contents providing method, ciphered-contents deciphering method, pirate identifying method, contents providing system, user system, trace system, ciphering apparatus, diciphering apparatus, and computer program |
摘要 |
A set of users is divided into subsets, and a decipher key is generated for each subgroup by using different key generation polynomials. A session key, that is, a decipher key for ciphered data is distributed so as to be deciphered with the decipher key of each user. Decipher keys of an arbitrary number of users can be revoked. On confiscating a pirate deciphering unit, the black-box tracing is performed by assuming users subject to revocation to be suspects. The tracer assumes the suspects, and investigates the suspects n times (n being the total number of users), so that all pirates in a coalition can be identified. <IMAGE> |
申请公布号 |
EP1331751(B1) |
申请公布日期 |
2007.05.02 |
申请号 |
EP20030002014 |
申请日期 |
2003.01.28 |
申请人 |
KABUSHIKI KAISHA TOSHIBA |
发明人 |
MATSUSHITA, TATSUYUKI |
分类号 |
H04L9/08;G06F21/10;G09C1/00;H04N7/167;H04N21/24;H04N21/266;H04N21/6334;H04N21/835 |
主分类号 |
H04L9/08 |
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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