发明名称 |
Video control system for recorded programs |
摘要 |
A video system includes a central facility and a terminal. Means are provided for playing a video recording medium storing a video program including a series of television fields including a first field containing both a random digital code encrypted according to a code encryption key and program identification data, and a second field containing an unintelligible video signal previously transformed from a intelligible video signal according to the random digital code. The terminal includes means for sending the program identification data to the central facility. The central facility includes a data base for storing and retrieving at least one code encryption key corresponding to the program identification data and means for sending the code encryption key from the central facility to the terminal. The terminal further includes means for receiving the code encryption key from the central facility, decrypting means for decrypting the encrypted digital code of the first frame in accordance with the code encryption key, and means for transforming the unintelligible video signal of the second frame to the intelligible video signal using the decrypted random digital code.
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申请公布号 |
US5054064(A) |
申请公布日期 |
1991.10.01 |
申请号 |
US19900501688 |
申请日期 |
1990.03.29 |
申请人 |
GTE LABORATORIES INCORPORATED |
发明人 |
WALKER, STEPHEN S.;SIDLO, CLARENCE M.;TEARE, MELVIN J. |
分类号 |
H04N7/167 |
主分类号 |
H04N7/167 |
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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